Shower CONTRAPTION…HELP!!!!

Any advise is very welcome! Previous owner was elderly, thus the bathtub and fixtures were removed. Presto, a pink tiled shower stall. The contraption is a shower fixture they used to use in hospitals/nusing homes. Both hot/cld wtr pipes do come out of the wall, then this unit T’s into a pivotal joint that is attached to an “arm”, at the end of this arm is the showerhead. Works like your elbow for moving the head up or down (hey, no snickering!) The mfg stamp is Milwaukee “Adjusto” Faucets,Inc. Here’s the hairpuller…PARTS! I need a new packing nut (the piece directly in back of the lever handle. Or new stems. Replacing entire unit, not an option. No exsisting access in tiled shower or 2″ thick original plaster wall on the other side (complete with plaster wire). House is 1887. I personally restored the walls myself (for 8 mo), there has to be a way to save this confounded contraption! Anyone know where to get parts for this? I know skilled craftsmen keep items that will be useful, (like mechanics keep car parts) especially when the item is no longer made…so take a look out in the shop, basement, and garage or let me know where I might find a whole unit or just parts… Thanks for your thought …. Damsel in distress!