Still had the Burgundy livery installed and was able to replicate the problem. MSFS contains fallback folder instructions for the livery to use when it can’t find a texture it needs. This is located in the livery’s texture.cfg file and should point to the parent aircraft. In the Burgundy livery it still points to the default 172, which was fine when they both had the same prop, but not now the prop is different.
So edit the texture.cfg of the Burgundy livery and change the 1st line from
fallback.1=..\..\C172TDI\texture. This will point the MSFS to the correct location for any textures it needs to source from the main aircraft for this livery.
Gave it a quick go and this solved the problem.