>>1307477>No mast and no motor.That's why it was cheap lmao.
Getting serious, if it has a mount like pic related on the transom you can fit an outboard motor but it seems unlikely on a boat that size. If it has a prop shaft and space for an engine built in you should get the type of engine it originally had, or go for another small marine diesel depending on availability of the original engine. You won't just need a mast, you'll need all the rigging too. If you have some rigging, it might need to be replaced due to age, wear, or differences in the mast it had and the mast you can get to replace it. Try to get one that's as close to the one originally installed or what the boat's set up for to have the least hassle. Going with a rig or engine that wasn't originally on it will take extra modifications but it's probably doable.
As far as sourcing the major parts, I have no clue off the top of my head. I can tell you that getting the mast stepped and putting an inboard engine in will probably require a crane and hauling the boat out of the water. If you're knowledgeable about engines and setting up rigging, you can do some of the work yourself, but start looking for boatyards that can at least do the heavy lifting.
I worked in a boatyard doing mostly odd jobs so I can't tell you what exact parts that specific boat needs, or what it would cost to get them.