I should have known when I got a really fast response to my query on the bathroom tub/shower faucet that things wouldn't be as easy as they seemed.
To their credit, Van Dyke's Restorers, where we bought the faucet and many, many other things through the years, were great. Initially, they said they would send me a similar unit to use for parts as they apparently no longer stock the exact same item. Great!
Then, I get an email saying they don't have anything they can send me. But they did refer me to the manufacturer, provided me warranty information and the model number of my purchased faucet. That was very helpful as I think our paperwork accidentally got tossed during the chaos of the marathon tub surround installation back in July.
The good news is I now have the schematic for the faucet kit so we can use that to determine what part we'll need to replace. The bad news is that Lawrence is on hiatus for a few more weeks at least. Ugh.
So far though, with some careful prodding, the shower has been semi-cooperative. (We're getting hot water and a steady stream but the pressure is down because about a third of the water escapes through the faucet. I can cope with this. For a while.
Cross your fingers.