Brian!
Thanks for that. Really, really useful.

It's all going together well. I'm going to use an Irvine 61 Mk2 with a BCM Pitts silencer for power. That's about 2bhp; plenty I think!
Controls will be pull-pull using wires with closed-loop compensators against Kavan steel pin hinges and I've decided to fix the landing gear using nylon bolts as a deliberate weak point. It's saved my Acro-Wot (Chris Foss design) many (many) times!
If you've had two of the beasts, you must have liked them despite the foibles.
Regards,
Carole