Hi rip-cord

I assume you figured out long ago the problem. As stanfortyman stated try to move up one space. You have to be connected across that plastic divider with those smaller FPE breakers to get the 240V. I have two or three FPE panels here and those 2-pole smaller breakers will go across the plastic divider without breaking it. Did you look at the clearance behind the breaker or try it?

Hopefully your all good by now anyway!