The 1345 was used I believe until 86 and in 87 they switched to the 1356 in f series trucks. They were offered in fixed yoke as well as slip yoke, and some had the option for a pto( Ive got two but they were hard to find and both came out of xl model work trucks).
Ive had problems with my 1356's popping out of gear due to worn shafts, I just pulled the cases open and shimmed the shafts with washers to keep everything tight. I would think that you could rebuild your tcase for less than what they want for that thing.