I bought 2 of these old drills at a garage sale about 15yrs ago for $1.00, I can't remember what I did with the other one but it was identical. What that is, is a bolt with the head hacked off into the drill and the threads mated up to where the handle was on the trimmer. 3 nuts holding it all together. I rig up things because I'm a cheapskate. I built a case tumbler out of another old drill and a coffee can. I even built a homemade drill press before I bought a real factory one cheap at a yard sale. Hey? I just remember where that other drill went!
The homemade press built out of a hand drill a bed frame and an old car jack.