I had a cap in basically the same position short on my Philco. It went from the plate on the ouput tube to ground. In my case, I have a push-pull amp but its the same idea. I was in the process of re-capping the set and plugged it in to check my work up to that point. Luckily I caught it before it took anything out, but the transformer did get warm.
If you really want to see what the transformer is, you'd need to calculate it's impedance. Basically take a known AC voltage and apply it to the secondary, and measure it on the primary. You use that to calculate the imepdance.
http://www.radioremembered.org/outimp.htm
RCA book says 7600 ohms for the 6K6 at 250 volts. Its just AM radio though, so it doesn't need to be exact.