RE: Building the original Byron P-51 Mustang
While I never built or flew a Byron kit, I always wanted one. I came close to ordering several times, but school clothes or something like that always got in the way. What I do remember about them was that while they did fly nicey when the engine was running, they didn't glide worth $0.02 when the engine quit running - which happened more often than you want to think about. For that reason, I would have the engine worked on by RCIgnitions and converted to EI and test run to get the most reliability possible. The way I look at it is you have a classic, you are going to spend a bunch of time and $$ to get it to the field, you need to pay for a little 'insurance' with the engine to make sure it runs and runs good. I have held off building a Zirolli P40 for about 20 years - but will start one next winter which will powered by a DA-85.
Dan