Thanks Keith, very interesting. The cutaway is probably the most detailed that I have seen.

As far as I know, the pressurised and high-speed versions were never built. I doubt if they would have been fast enough or high-flying enough to out-fly a He219.

You may remember I said that someone had kindly bought me the Revell Lancaster kit, which I will probably have a go at even though it is not my current speciality. I have a vague idea of converting it into a Dambuster version, in which case the drawing you have supplied of the Upkeep installation is as good as I'm going to get. (No good going by the 1954 film; the mines were shown as projecting further from the fuselage than they actually did. I wonder if Peter Jackson will get it right if he gets round to a remake?)