Thanks for all the comments

I'm certainly going to try and finish this one off!
Making a cab isn't a problem, as I've already made Corris 1,2 and 3 in the past (2&3 as cabbed versions). Also the TR model of Sir Haydn previously made, is Corris no 3 repainted to represent how it looked when first running on the TR.
The problem with the current Sir Haydn is that it has been considerably altered from its Corris condition and there appear to be no plans available of it in this condition. I've even asked the Talyllyn to no avail (though, I might try them again).
By the way Andrew, whats the other loco?
Cheers,
Kevin