Well, once upon a time I had the idea of replacing the wings with larger scale F-5 wings and replacing the engines with J79s as a starting point (this was way, way long ago, before I really got into the business). I still think that re-engining is a priority and larger wings, too; the larger wings actually giving you a place to carry stores.
Scalorama 1/48 to 1/72 for a 2001 Orion III space clipper style space craft
Mog
>^-.-^<