So, after some testing I’ve come to the conclusion that the Sound of Steam Card on my 1985 MPC semi-Scale Hudson, isn’t usable. The loco itself doesn’t require a tether, being an open-frame motor with a mechanical reverser.
I have an “air whistle” tender which was rather scruffy, but works fine. The MPC tender has a rather nice cast body, so with some experimentation I found that I could re-drill the whistle tender base, and fit it in the cast body. I’ve lost the 6-wheel trucks (the MPC trucks don’t have rollers fitted, but I dare say that can be remedied if I can find the parts).
So the loco now has its original tender body in matching TCA colours, an air whistle and smoke.. which I think fits nicely in character.