Shipdam Airdrome Dio

Minicraft, the popular 1/144 scale manufacturer, makes a few 1/72 scale B-24's. I'm not sure how good they are though.

Ooops, sorry about the B-17 suggestion....I saw B-24 and thought B-17 for some reason.

Best 72 Liberators are the Academy kits.
Preiser makes a good set of WWII airfield figs.
The Airfix control tower (and the vehicles) are 1/76 but should work. The tower is pretty common among most of the RAF bases and US bases.
There are also lots of resin kits out for US vehicles etc.

Actually, Airfix puts out more than I thought. I just checked Squadron.com (www.squadron.com) to see what they have out and there's several airfield kits available.

RAF Refueling Set
http://www.squadron.com/ItemDetails.asp?item=AX03302

RAF Emergency Set
http://www.squadron.com/ItemDetails.asp?item=AX03304

RAF Recovery Set
http://www.squadron.com/ItemDetails.asp?item=AX03305

RAF Control Tower
http://www.squadron.com/ItemDetails.asp?item=AX03380

RAF Personnel
http://www.squadron.com/ItemDetails.asp?item=AX01747

Airfix also puts out a B-17G kit, but I would think that there are better kits out there in terms of quality.

Airfix has a set of RAF ground crew which I believe comes with a fueling truck, and Airfix also puts out an airfield tower set. I'm not sure what differences their might be between British and American ground crews/airfield structures, but they might be a place to start. I haven't worked with either package myself so I can't say how good the quality is, although from the other Airfix kits I've worked with in the past I would guess that they are pretty basic in detail and whatnot.