The Helm Wind did start out as 'APT-Thing', but I decided I preferred the Helm Wind. I wouldn't object to having both, but I don't really go for the shape of the APT, so I probably won't do it
Working on this now. Can't decide what's best length, given a 6/8 engine...
* 6/8 coach, which can be combined with a 4/8 coach or van for a 16/8 (1 tile) train
* 13/8 articulated coach pair, which won't make a nice 1 tile train, but two of these with the engine in the middle gives a perfectly symmetrical 32/8 (2 tile) train
The second option is a bit weird, but the symmetry would be nice https://www.warwickshirerailways.com/lms/lnwrk152.htm