Lovely little lathe
Manufactured in 1952, if im not mistaken. a quick check makes me think the model number is 101.07403
All of the craftsmans made before 1958 typically had the gears you need to rearrange for cutting different threads (changewheel gears), after 1958, screwcutting gearboxes were installed on most of them which is my preferred choice. Changewheels drive me nuts
but they do the job regardless just a bit more fiddley to get the configuration you want.
Looks like at some stage the power switch failed and theyve replaced it.. hell of a switch they have fitted.. may want to check that out, even consider replacing it.
Here's a parts list for it, which you may want to file away
http://shdesigns.org/Craftsman-12x36/Craftsman12x36.pdf
Get a pair of calipers on your leadscrew too. It distributes power to your cross slide as well as your carriage. If the lathe was used as part of a production line and done alot of repetitive tasks like facing, you may find that the leadscrew has worn in certain places. Just measure it all the way along the leadscrew and make sure the widths of the thread are even.
If you find its stalling on you, you have it in the wrong gear. go light with it until you learn its limits