I semi-collect Thor brand tools... I've got a hand drill with a 5/8" chuck, it's about 20lbs. God help you if it gets stuck, because it doesn't have a 'trigger' it has a big sliding bolt like a table lamp. Letting go won't save you....
That one looks newer than any I've seen before, but I don't know what their years of production were. But, you can look for 'modern' ammenaties.. Does it have a reverse? Only one of my Thor drills has a reverse :P