Enjoyed going thru your thread young man. Here some info on trans (speedo) gears from Hot Rod
https://www.hotrod.com/articles/cali...-speedometers/ I had 2read it a few times, & still cornfused! 4 stubborn rustd bolts, nutz, get mapp gas cylindr/torch head (not a propane torch, cuz it burns hotter than propane). You may have 2 heat/ cool 2,3 times to get stuff lose! I mix dot 3 brake fluid w/ older type g.m. tranny fluid in a oil squirt can, let soak overnite if possible, it’ll wick right in to even the most rusted fasteners. For electrical problems, check grounds first, sometimes Harbor Freight has a little ohm/volt multimeter coupon 4 free, it’s a lot cheaper than guessing/replacing expensive electronics. Read up on it, one guy replaced alternator, voltage regulator, starter only to find all problems were caused by dirty or no ground wires! And sooo we learn by doing. You are in my prayers, brother. God Bless