Howdy! nice, sounds like a fun and cool project. Does the car have an owner's manual? should have the fusebox schematic in there I think. In any case after the car the next things you should always buy are an Oldsmobile chassis service manual at the least, then a Fisher Body manual, and a factory assembly manual, all readily available. Then every catalog you can lay your hands on, online works but is a pain when you're covered with grease, my garage doesn't have internet or cell phone access purposefully.
I like USA parts supply, catalog is great, online is plain text lines. Fusicks seems popular, they seem to have the best reputation. Year One is either loved or hated, I use them sometimes and have no major problems, watch for backorders on the most common parts though. Supercars Unlimited, OPGI, National Parts Depot,The Paddock, Restoration Specialties for fasteners and all kinds of neat stuff, Eastwood for specialty paint and resto supplies and tools. Smartshoppers has the best prices for primer and body supplies and tools, spraygunworld has LVLP if you have a small compressor. I like the local NAPA for all the mechanical stuff. Rock Auto online has all kinds of good and obscure mechanical parts too. I will see if I can rustle up a fusebox schematic and post it later after work if you still need it.
Allan