Nice map. I had some thoughts about it. There quite a lot of sea around, which does not increase the fun by playing that much. Ok, I know, this is a specific British Problem, but anyway... ; - )
I thought how to increase the land part of that map without having a too huge map. So I did the following:
1. I turned Britain around by 20 degress. I do hope wholeheartely that Her Majesty will forgive me.
This allowed me to cut a relevant amount of sea on all sides.
2. I shrinked the West of Ireland by some 150 px, as there not that much big cities, industries and traffic systems. Any Irishmen which fell offended by that should ping me when meeting me in a bar. We will clear that problem over some beers.
3. I shrinked the north of Scotland by some 100 px. Well, Scotsmen, no way to solve it the Irish way, as I don't drink Whisky.
4. As the Eurostar seems senceless without serving people on the continent, I added a simplified, manipulated version of the French coast, whereas a part of it moved to the north. Now we have a real channel and space for some French cities. I am sure, the Bretones wouldn't claim, as their erea is even bigger now.
5. I scaled the ppm to 2560 by 3813 px, which is almost the original size, but with some 20% more land in width and height.
I hope that might increase the fun. Feel free to go on improving it. I am missing this nice river through London, btw.http://simutrans.bilkinfo.de/britishisles-2560-3816.ppm.gz
(gzip, 2.8 MB)
Hoping to have fit your needs, I remain