Yes, the LDA Y, the LOC & DCA VOR are both at the Airport
The LDA Z, the LOC is across the river from the Airport, so the approach course is different
I assume they installed the LDA Z, to give an approach course with an easier turn to the runway.
Then , to add to the confusion, it seesm the LDA Y use to be ROSSLYN LDA RWY 19, and maybe then, did have a GS ?
Note : It says
LDA / GLIDE SLOPE
RADAR REQUIRED