That will be an impressive looking project - the B-17 that has been Flite-metalled! [8D] Regarding the 70-90 mph turbine model, I doubt if you'll find any scale models that could fly that slowly and comfortably so, but there are several sport models (like Boomerangs) that would be comfortable to fly, I'm sure, at that speed. Some would be even proud of you if you could figure out how to Flite-metal one - that red/wht/blu color scheme is getting a bit old!