I have some of those transformers (mine are Baldwin, and I expect yours are too). I'm using mine with 6CW5s. Trioded pentodes (or real triodes) are a viable option, too.
What tubes with 3.3K p2p output transformer? I've got a pair of old output transformers that were used with 6L6s to a 16 ohm load. I'd like to use and 8 ohm load so it will have half the primary load of 6.6K, right?
Power has to be about 30 watts minimum from the heft of the transformer. The amp was originally 6L6 to a 16 ohm load and I would like a 8 or even better 6 ohm load.That might go well with Class A operation. Ye Olde Junke Box yielded up a NIB Stancor OPT with a 4K4 primary. That one was obviously designed for Class A 6L6s (giving a 2K2 load to each 6L6). It served quite well for Class AB 6BQ6s, but it turned a 40W amp into a 30W amp, since that's what it was rated for, and the OPT rolls over and dies before the finals actually hit clipping.
What's its power rating? You might be able to dig up some finals that might work quite well in Class A (though TV horizontal deflection finals aren't those types).