Online video sure tests the limits of the Internet. It is possible to download Google Videos if you install the Google Video player:
http://video.google.com/playerdownload.html
Unfortunaetly the download file is larger then the online file - might take a week on dial-up to download this 30 minute film!
re. Mark II Lancasters, as you mentioned 514 Squadron (Waterbeach) did fly Mark II's these Lancs used Bristol Hercules radial engines, all other Lancs used RR Merlin engines.
If you are able to view the film you will notice the Lancaster featured is equipped with Merlin engines.
Lancaster A2-C was actually a Mark II.
Here is a site with some still images: http://www.hilaroad.com/family

Regards, E.W. Campbell