I think I'm just going to put the 72 back in the Snipe. That's already one engine size larger than the 56/62 I had flying the equivalent size and weight Puppeteer. And that engine seems a lot more reliable. Also I'm wondering whether torque from the larger engine with larger prop might not be a problem on take-offs. The gear on the Snipe is both tall and narrow (in other words "scale") and the rudder is relatively small (also scale).

And the fact is that the model has already flown with the 72 and if there was any problem it was that I was flying it too fast. Also the 72 will allow longer flight times. I'll keep playing around with the 82. Maybe I can eventually get it running well enough to use in some future model.