The RCtimer motor I recommended is over kill for that size Lancaster. It's one of my candidate motors for a 2m Dehavilland DH-91 that I plan to build this winter.
I have another recommendation: http://www.hobbyking.com/hobbyking/s...idProduct=5684
I have 8 of this series (in the 2209 and 2217 sizes) in various planes and they are nice motors. I think it would easily turn 7x5 props.
Here's another possibility: http://www.hobbyking.com/hobbyking/s...er_1534kv.html
I haven't gotten my hands on it yet (backordered of course.)