As it turns out, I finally found the B-52. It's at
http://www.flyingbaer.de/ Then go to "FMS" then "George Gerdes" then to page 11. It has an X-15 under one wing.
I also found another great site. It is
http://www.rc-sim.de/dl_engine_eng/i...aa45bc47e8f178 On this one, you might have to find your way there by going to "FMS" then "Version 2.7" then "FMS 7.x planes"
I found both the B-17 & B-29 on one or both of these sites.
Let me know how that works out for you.
Brad