Thank you so much to jamespetts and the other contributors to Sim-Ex and Pak128-Brit-Ex for all your work. Once again you've made my summer holiday a much more pleasant experience.
I notice that the 0.9.1 simuconf.tab file contains this comment:
# Draw the signals on the left.
# (In Pak128.Britain, this must be set to 0 until the signals are re-drawn to suit
# this setting).
signals_on_left = 0
Is this comment still applicable for P1k128-Brit-Ex 0.9.1? I've started a game with signals_on_left set to 1, and we seem to have workable signals. As of the 1850s, they are the 'railway policeman' type signals. Is the game going to come to a crashing halt at some point? If not, then perhaps the comment should be considered as a (very minor) bug.
Signals on the left technically work fine. It's just that 0.9.1 doesn't have left-hand graphics for them so you'll have railway policemen facing away from the track.
Rollermaterial is correct: there is no insuperable technical obstacle to using the signals on the left setting, but the graphics for signals used in that version of the pakset make it cosmetically suboptimal. The new signals in the later versions of Standard and the devel-new branch are intended for use on the left.
I just realized that I never replied to this. Thank you very much for the information. That game is still ongoing, so it's reassuring to know that the problem is only cosmetic.
I should note that the new signals that work on the left are now available in the nightly releases.