Spider Robinson not SF? Well, if you don't think Callahan fits, try Stardance and its sequals.

And, for those of us who haven't quite grown up, there are all of the current crop of SF authors, such as David Weber and Mercedes Lackey.

"Paul French"? That would be Grandfather Isaac and his Lucky Starr series of juvies.

Daithi, here is a copy of By His Bootstraps.