Henry,
The model 754 did use the
SMALL air fillter assembley. This makes sence as the Kohler K-161 used the smaller air filter and the engine was sold to Wheel Horse that way. There would be no need to change air filter housing at the Wheel Horse plant just to make it look like the Kohler K-181.
I know it was a few years back but the 754 you sold me did have the small air filter assembley.

I picked up a K-181 air filter assembley at Portland from the guy I bought the 552 from .... it was a package deal.
Wild Bill in Richmond, VA