No problem. At the moment your map still doesn't seem to be showing? As to information from Kew a fully loaded two terabyte hard drive would about cover it! Of course, it goes without saying that your own work takes absolute priority. If you have time, and only if, have a read of http://www.wwiiaircraftperformance.org/ and http://www.spitfireperformance.com/spit1vrs109e.html - there are some interesting documents cited...in the meantime enjoy your research and don't get blocked again. Cheers!