The 5F2 chassis works great. It requires very little in the way of modification to work with the 2Stroke design (with the Hammond or Weber transformers at least). The Magnetic Components PT (40-18027) looks like it would work, there is only 2A available for the rectifier and heater circuits, 3.5-4A would be more versatile if you decide to add something later. The MC OT specs primary taps at 5k & 8k, the original 2Stroke spec calls for 2-2.5k so you might want to consider that. I did not check around the MC website for other possible single ended OT’s. Triode Electronics is helpful about what Magnetic Components products are available. Their phone: 773-427-8823