The first problem taking track onto the extension is that the joint between the two baseboards is a bit rubbish. I used to slide the chapel back over it to hide the worse of our dodgy woodwork but that's not going to be an option now. The gap must be filled.
Ideas considered mostly included covering the station end with clingfilm and then smearing Polyfilla or No More Nail glue over the end of the extension board, clamping them together and letting the stuff set. The clingfilm would stop the boards being permanently bonded. In thoery.
My Dad wasn't convinced by this hi-tech stuff and decided to have a go with some thin plywood and a sanding block. After a fair bit of fiddling, he managed to shape some lite-ply to fill the gap and extend down the board some way so it can be stuck in place. We've still got a problem at the sea wall but I might just pretent not so see that for the minute.