Man, you have a lot of engines Marv. I like the Scotch yoke and will have to build your horizontal version
to go with my vertical mode.
I liked them all but this one may be a good match for my vertical:

STANDBY.jpg Photo by mklotz | Photobucket

I have been to john-toms and have several projects planned from there. That is the super source for old engine plans.

Thanks for the links,
Cheers, JR