I have one of those old Ford starters,and have used it to start engines--years ago I had one set up with a pair of handlebars and a Ford starter relay mounted on the starter,so by pushing a button I could activate the starter--I ground down the shaft square,to allow a 1/2" drive socket to fit on it,and used whatever socket fit the flywheel nut...it was a bit dangerous,sometimes the socket stayed on the nut after it would start up,and you pulled the starter away,and it become a missle!..
I had another starter like that one mounted on an old hand truck,so I could use it to start engines with a belt,by leaning back on the hand truck,and tightening the v-belt..like your setup,the belt could prove to be a hazard,but I never got injured using it...
I lent the thing to an elderly friend who could no longer pull ropes,and owned a lot of old engines that were rope start--unfortunately, he passed away,and I never got it back..I think his kids scrapped it,along with most of his extensive collection of "old things"..
