Sorry I only tested this with my own 172 livery. I downloaded and installed the burgandy livery with the aircraft.cfg change I suggested and got the same problems as you with non functioning engine instruments.
The problem is that the livery creater has included a “model” folder in their livery. This was only required when Asobo stuffed up something and all liveries failed to load. Asobo corrected this a long time ago and the “model” folder is no longer required. As the JT-A also utilised a model folder, this caused a conflict and stuff stopped working. Repaints should only have a texture folder or risk compatibility with mods like the JT-A. Even updates made by Asobo to the default aircraft can also get tripped up by liveries not done correctly.
So you will need to delete the “model” folder if you want to use the burgandy livery with the JT-A. Unfortunately this also necessitates updating the layout.json file and further changes to the aircraft.cfg file. The livery creater also hard coded some of the aircraft details in the aircraft.cfg file, so it would always appear in MSFS with the a Cessna C172 Skyhawk G1000 description rather than the Cessna 172 JT-A description.
I have pasted copies or the updated aircraft.cfg and layout.json file at the bottom. Just cut and paste these into the existing files (overwriting everything), dlkete the mdoel folder and you should be good to go.
I know the author of these liveries so will drop them a note about changing their liveries so they can easily be adapted for the JT-A.
Aircraft.cfg
[VERSION]
major = 1
minor = 0
[VARIATION]
base_container = "..\C172TDI"
[FLTSIM.0]
title = "Cessna 172SP Skyhawk G Burgundy" ; Variation name
model = "" ; model folder
panel = "" ; panel folder
sound = "" ; sound folder
texture = "BURGUNDY" ; Blue texture folder
kb_checklists = "Cessna172SP_check" ; Procedures/Checklist sibling file name
kb_reference = "Cessna172SP_ref" ; Reference information sibling file name
description = "Custom description" ; Variation description.
wip_indicator = 0 ; know if the variation is good to go or still WIP : -1=Disabled, 0=Rough, 1=1st Pass, 2=Finished
ui_manufacturer = "TT:AIRCRAFT.UI_MANUFACTURER" ; e.g. Boeing, Cessna
ui_type = "TT:AIRCRAFT.UI_MODEL" ; e.g. 747-400, 172
ui_variation = "Burgundy" ; e.g. World Air, IFR Panel
ui_typerole = "Single Engine Prop" ; e.g. Single Engine Prop, Twin Engine Prop, Rotorcraft, etc
ui_createdby = "Asobo Studio" ; e.g. Asobo Studio, Microsoft, FSAddonCompany, etc
ui_thumbnailfile = "" ; app relative path to ThumbNail image file
ui_certified_ceiling = 14000 ; service ceiling / max certified operating altitude (ft)
ui_max_range = 640 ; max distance the aircraft can fly between take-off and landing in (NM)
ui_autonomy = 5 ; max duration the aircraft can fly between take-off and landing in (Hrs)
ui_fuel_burn_rate = 54 ; average fuel consumption per hour (lbs/hr) - reminder: fuel density is ~6.7lbs per US gallon
atc_id = "VH-BLR" ; tail number
atc_id_enable = 1 ; enable tail number
atc_airline = "CESSNA" ; airline name
atc_flight_number = "172" ; flight number
atc_heavy = 0 ; heavy?
atc_parking_types = "RAMP" ; "ANY" / "RAMP" / "CARGO" / "MIL_CARGO" / "MIL_COMBAT" / "GATE" / "DOCK"
atc_parking_codes = "" ; Comma separated and may be as small as one character each
atc_id_color = "" ; color for the tail number : i.e. "#ffff00ff"
atc_id_font = "" ; font for the tail number
isAirTraffic = 0 ; Is the plane usable for air traffic
isUserSelectable = 1 ; Is the plane selectable by the user
Layout.json
{
"content": [
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/aircraft.cfg",
"size": 2025,
"date": 132680126465935250
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_FUSELAGE_ALBD.PNG.dds",
"size": 8388736,
"date": 132503541148070000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_FUSELAGE_ALBD.PNG.DDS.json",
"size": 102,
"date": 132442318480000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_FUSELAGE_COMP.PNG.DDS",
"size": 2097280,
"date": 132465938881580000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_FUSELAGE_COMP.PNG.DDS.json",
"size": 191,
"date": 132421482898860000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_LIVERYCOLOR_ALBD.PNG.DDS",
"size": 5616,
"date": 132442317080000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_LIVERYCOLOR_ALBD.PNG.DDS.json",
"size": 102,
"date": 132442317080000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_LIVERY_ALBD.PNG.DDS",
"size": 4194432,
"date": 132463514405590000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_LIVERY_ALBD.PNG.DDS.json",
"size": 119,
"date": 132442317100000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_TAILLANDING_ALBD.PNG.DDS",
"size": 8388736,
"date": 132505454321300000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_TAILLANDING_ALBD.PNG.DDS.json",
"size": 102,
"date": 132442317260000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_TAILLANDING_COMP.PNG.DDS",
"size": 2097280,
"date": 132505458531310000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_TAILLANDING_COMP.PNG.DDS.json",
"size": 191,
"date": 132421482900210000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_WINGS_ALBD.PNG.DDS",
"size": 2097280,
"date": 132464406696050000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_WINGS_ALBD.PNG.DDS.json",
"size": 102,
"date": 132442318560000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_WINGS_COMP.PNG.DDS",
"size": 2097280,
"date": 132465953269600000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/C172SP_AIRFRAME_WINGS_COMP.PNG.DDS.json",
"size": 191,
"date": 132421482901880000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/texture.CFG",
"size": 237,
"date": 132444284900000000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/thumbnail.JPG",
"size": 263441,
"date": 132464129646750000
},
{
"path": "SimObjects/Airplanes/Asobo_C172sp_AS1000burgundy/TEXTURE.BURGUNDY/thumbnail_small.JPG",
"size": 61837,
"date": 132464130898670000
}
]
}
And if not, I am in good company!