I'll try again,
Not too much I can say about the design Bill,
I made it by basically measuring for the frame by laying a tape by the motor and thinking "that oughta be long enough and that oughta be wide enough" and then sitting the motor on the bench,(actually an XS650 motor originally ) and laying the frame around it.Then working out I'll put some mounting lugs about there, there and there, and then cutting and drilling some lengths of steel to bolt it up.
When I wanted to mount the Honda motor I just welded some more mounting lugs to the frame (once again using my eye-ometer).
If I can get the photos to upload you'll see another couple of uses for the frame that I've since come up with.