Thanks Tiffany!
Like I said, I'm still missing a couple of Pennsy's crazy, big engines, the Q1 and the S2 Turbine. Needless to say they only had one each of them and they weren't very successful so I won't bother chasing them. The S-1 was a one-off engine two, but led to the T-1.
These big engines, even though they say O-72, barely look good on O-96. I wish I was working with O-120 or higher, but it takes great amounts of real estate. I can get a lot of length with my new design, but I'm restricted in width to 15 feet. Oh well... we all have our limitations.