Very cool. If you find yourself in need of a step-up transformer, I think I can lay my hands on one for you. We permanently decommissioned a couple of dead heaters at work, and they were powered from step-down transformers. I know they were fed from 277 but I'm pretty sure it also has a 240v input tap and a 120v output. Wire it backwards and you've got 120 in and 240 or 277 out. Not sure the amperage offhand but the transformer itself is pretty close in size to a stock PL 700 transformer. Let me know if you need it, and I'll dig it out of the ceiling.
otherwise you could really cheat and use a couple of extension cords plugged into outlets fed from different buss lines in your breaker box. Hot to hot should give 240v. If you get 2 on the same buss, it'll be 0v. Thats not really a safe way to do it, but it does work in a pinch.