Yes, I've tried everything, maybe these roms aren't switchable after all :(. Maybe Chris could take a look, looking at an actual switchable rom (labyrinth £10), you can see in the hex editor as you switch the dip, the byte at a certain location changes corresponding to the price of play in hex... 0A - 10p, 14 - 20p and 19 - 25p. Maybe they could be hacked but I don't have the time to look into it at the minute.
Anyway here is Spinx £6 token roms, these are switchable via bank 2 dip. Switch 6 is 10p play, switch 7 is 5p play. Default is all off for 20p play.
J
Sphinx V4_2__5_10.bin