Congrats on your Capri purchase. They are a bit of a roller coaster ride to own, emotionally... fun to drive, frustrating when they break, but mostly fun to drive!!!
Your car rolling in PARK may simply be a cable adjustment issue, especially if it is intermittent. When you advance the lever to get to park, it may not go *quite* far enough sometimes. Worse case is some teeth or cogs may be missing from the PARK mechanism internal to the tranny. Keep using that emergency brake (which you should do anyway with an automatic) and you probably will be OK.
The brake light is a little ominous, coupled with your watering can reservoir. The brake light serves 2 purposes, to let you know when the emergency brake is engaged, and when there is a pressure imbalance detected in the brake master cylinder. When rust gets into the brake system (from water condensing over the years) it starts clogging little tubes in the master cylinder that lets fluid move around properly. Your brakes won't necessarily fail, but they won't act as good as perfect, and brake pads one one wheel can start wearing out prematurely. like in 10,000 miles or so. So, you absolutely need to get the non-metal original equipment reservoir installed and the brake system flushed. This might break loose the rust, but worse case would be a new master cylinder, not too expensive to buy, but a couple hundred at a mechanic's.
The hood prop holder can be purchased at Autozone, they sell a pack of about 5 of them. less than $10, one of those in the pack is a perfect fit.
What do you mean by needing a brake light socket???
Inside or outside door handle? I'm traveling through Tampa this week and could drop one off to you, compliments of a Capri nut with a garage full of spare parts...Chris