Hmm I tried to reply last night but something went wrong with my post I guess.
Thanks for all the responses everyone. Yes, the B-17 does not have covers on either the tail wheelwell or the portions of the main wheelwell that the strut comes through. So no need to worry aboubt that at least.
I'll need to find some way to simply position the wheels halfway inside the wells at the appropriate depth, and position the struts in approximately the correct position as well.
It's not really a question of "can I do it" (I can. It won't be perfect, but I'm not a perfectionist) as "why does the kit's packaging say it has gear position options when it doesn't?". The kit does have a ton of extra parts that could be used to build a wide variety of B-17s, but no extra bits for the landing gear.