I just bought three OS.61SF ringed side exhaust engines on eBay, with the same intention of putting them in older pattern designs.

I also have a YS.60 roundhead side exhaust and a Rossi AXE .61 side exhaust that I bought for those times when I want to let'er-rip with an 11x7 prop. Now to get some old pattern ships built in which to fly them.

I think I'm going to forego using a tuned pipe and just stick with the PSP and Jett mufflers. No disassembly needed when setting up and breaking down for transport. Getting lazy, I guess.