Spinwelder Race Car Builder, Weld a dragster and a Can-Am special! Rev them up and run ’em! Cool toy from Mattel No. 7331. Copyright 1974. Runs on a 6-volt lantern battery, that’s a big flashlight. My grandfather still uses one like that. One of my boys picked this up, but he hasn’t built it. It’s probably worth more if he doesn’t, but I won’t stop him if he decides to do it.