Jim S,
Welcome to the forum. Answers to your questions on paint and tranny oil can be found in the FAQ link near the top of the page as well as much other useful information. Tail lights and seats are available from several of the fine forum sponsors at the top of the page. Low Ash Engine oil and HyTran are available at your nearest Case IH dealer.
Not sure on exact production numbers but there weren't many made as they were only introduced about 6-8 months prior to the new Quietline series being introduced in 1974. They are definitely worth restoring. I'm in the process of restoring one myself currently. Been a slow process for me as time permits. Replacing all worn parts, new seals/gaskets on the Hydro pump, fresh HyTran and filter on the transmission, derusting via electrolysis and repainting back to original colors. Also plan to take the balance gears out of the engine and have David Kirk's balance kit added to the crankshaft.