I only knew a couple of older modellers interested in combat when I was a Junior-Senior contestant, and wasn't able to keep track of either of them.  Mostly, I practiced with some equally inexperienced young people, using the same planes we also used in contests (Nobody flying wings when I started, then Half- Fasts, then a mix of Quickers and Whatzits).  I only had one "main" engine, and a backup that exchanged places with it when some sort of repair or renewal was in order. 

Then, as I was finishing college, I found several people my age with a similar interests, and we all had more money to budget for our hobby than we'd had as kids.  Instead of using that period's Sneekers and VooDoos, we each built several Junior Satans, and used 19-sized engines on suction.  The grass field we flew over had soft dirt, instead of the more typical hard-baked clay we often see as unimproved soil around south Texas, and when the Jr Satans were covered with a tough covering made from a mix of fibers, including nylon (was rayon the other part? or was it silk plus Rayon?  "SilRay"?), these Jr. Satans we had survived countless crashes. 

There were four of us that summer, at first, although I was the only one making the trips to enter contests, and only one other of the four ever entered local combat events, although he wasn't necessarily any better at it than anyone else, just more daring.  When several of the Jr Satans  finally did take more damage than repairs could bring them back from, we chose Flite Line's Demon kit as our next "group model", and upgraded the 19s from suction to pacifier tanks (maybe we used pen bladders -- it was 1961/1962 or so). 

I don't think we used crankcase pressure and hard tanks on the 19s, although those were what was used most for competition at the time.  Three of us kept flying together and practicing combat flying through the next fall and winter, and it was great fun, but the third member's lack of a competitive urge began to be too much of a disadvantage, such that he lost interest.   However, by sticking with a lesser powered engine, and standardizing on one design, we had created a variety of "Speed Limit" already, thirty years before that idea caught on in the rest of the country. 

If Houston wasn't so comparatively far away, there are a half dozen combat fliers in that area who practice at Scobee field almost every decent weather weekend that there is no combat contest locally or somewhere else to attend.  When you fly that often, you really stay SHARP.  Anyway, just reminiscing, and avoiding a total Hijack of a thread elsewhere here.