Does anyone know if anyone makes a shower/tub faucet that is on 6" center on the hot and cold knobs?

We are trying to get an old family home ready for a new tennant and have a problem with a tub and shower faucet. The push up diverter does not seat properly because of its very old age. The house is on well water and the flow of water through the valve body is also greatly reduced. My father believes that the existing 3 hole valve is an old Sears variety. About 6 years ago, we converted all of the iron pipes in the crawl space to CPVC, but did not change out this bathroom. We are not wanting to redo any of the tile in the shower. It would be nice to find another 6" OC 3 hole valve, but so far have not found one.

We figure our other option is to put in a faucet kit we saw at Lowe's that is labeled for Mobile Home which has a full shroud around the entire faucet and knobs. At least this would allow us to enlarge the existing outer holes and then seal the new shroud/escutcheon to the tile.

Any thoughts on finding a 6" OC 3 hole valve, or other ideas on how to retrofit?
Thanks,
Lyle