[shorty]

They are Haben built units.

 

[shorty]

They also made tillers for Ariens.
The tiller in my avatar pic is an Ariens built by Haben.

 

[shorty]

One thing I noticed on my Ariens S-16 from the mid 70's era, is a lot of carrage bolts. On the Gravely 18H, which is the same as a Ariens Gt18, the holes are tapped and regular bolts are used. I am guessing that it was the standard at that time.

 

[shorty]

No specific info here. Each brand had their own mounting system. On the tillers, they were the same up to the pivot point.