I can't speak for the Lancaster just yet, but I just downloaded the B-17G-80 002
Chow Hound Lighted, AvH HG Shared files and all five of the Effects and Weapons files plus the BDP Nuker from AvH.
After installing all the effects and weapons to a fresh, unmodified CFS3.1a install, I then ran the BDP Nuker as instructed. No problems.
I then installed the B-17 and the Shared files and ran CFS3. The B-17 showed up in the USA aircraft list immediately. Selecting the B-17 for Free Flight, it exploded and burned in front of the hangar. This is not a real problem, just add the AirbaseFix to your install - the B-17 is quite big and the fix increases the distance the aircraft spawns from the hangar.
Selecting Quick Combat, the aircraft loaded and flew as it should - not very agile or fast and somewhat slow to get off the ground. Rather like reports of the real thing! If it helps, the instructions on the web page for the WepPak_041708 are the ones I followed.
AvH does not have the best documented downloads, but these certainly seem to work.
Edit: the Lancaster installs properly too.
HTH