[x-bird]

Before you jump in buying any parts at all, (one of the "original" sins of new buggy owners is to spend money on things they don't actually need or are not quite right) get your engine up on a work area and take some pictures to post. That particular transmission assembly will not work with a reverse gearbox. It came from a buggy that did not have them and the final shaft is too short. Your engine still has it's transmission assembly in it. the final shaft looks kind of rusty. your carb is in the box, it may just need a thorough cleaning. to be honest, i dont' think you need to buy a lot, just lay out what you have, give it all a thorough cleaning and we'll help you figure out what's usable first.

Lack of TLC, elbow grease and a methodical repair or problem analysis plan has led to many of these buggies ending up like yours when the owners gave up on them instead of going through things one by one. the carbs gumming up from "today's" ethanol mix gas are the biggest culprits, followed buy aging electrical parts failing.

electrically, it looks like you're missing the starter solenoid (round rubber holder in the electrical "box")