Last night, we rented a small auger from Home Depot and picked up the replacement faucet parts. We also bought a big bottle of chemical drain cleaner and priced the pieces we would need for the renovation.
The replacement faucet parts took about 5 minutes to install so we have hot water service to the tub again. While I was in the plumbing parts aisle at Home Depot, I did also ask about the coverplate for the shutoff valve. (The fixtures were probably made in the mid-70s; our townhouse was built in 1977 and I am certain this is the original plumbing). They'd never heard of such a part, but did suggest I go directly to EMCO, the manufacturer, who have a "showroom" in Victoria (who knew?), near the Town and Country mall. I have emailed them to ask if the part is still available.
The auger? Totally worth the $9.00 rental price (that was a "4 hour rental" which was due back by 9 a.m. today). Hubby ran it in through the sink drain and, thanks to the auger's drilling ability, was able to clear a very disgusting clog with about 20 minutes of hard work. While he cleaned the auger, I replaced the trap under the sink and wiped-down the tub. Then we each had a shower. Ahhhhhhhhh.
The drain cleaner, unopened and unused, is now in the cupboard, for emergency use only, but I am happy we were able to clear the drain without the use of harsh chemicals.
We are still determined to replace the bathroom fixtures very soon... so expect more to come on this subject.