The Ottawa Buzzmaster could be purchased with a 6HP or 7HP Wisconsin AEH or AEHS engine.
These are scans of MY Buzzmaster manual..
The Buzzmaster could be had with a post-hole digger, the tree feller (shown), a vertical saw blade for cutting up wood and a sickle mower.
I've never seen anything in person but the tree felling model.
This is My 1947 Ottawa Buzzmaster
It's missing the blade guard. If you have a spare one (yeah right), let me know.
It has a Wisconsin AEHS
Wisc. Serial # 919495
Ottawa Serial # H1059
It takes a Champion D16 spark plug
.030 Gap
Uses a 105B or 105C belt to run the blade
4.00 X 12 tires