Hello Tom, just seen your fiz-ogg (sorry visage
) in a 1962 Aero Modeller, don't ask what I was doing looking at it, it was on the shelf in the office and I picked it up to look. As to the thundertiger I don't know that much about them, having been warned off them by chaps in our club, don't know if their comments were fair though? Have you had a look at the Magnum 61FS, its very small for a 61, and the chap that owns my local model shop swears by them! He tunes them, and modifies them for customers, I have one with a stunt venturi ready for a model, haven't tried it yet though!
Cheers