OK, I tried the wheel slamming technique suggested by Vince. It seemed to help but not enough.
I got the wheel off and checked the "play" on the right main tube. It's bent, all right -- the bottom end of the fork moves about 1/2" - 3/4" when I rotate the main tube.
Question: what if I were to rotate the tube about 1/4 turn, so that instead of being bent backwards, it's bent inwards (towards the wheel). If I could then get the wheel back in (might be a tight squeeze), it would push the forks apart, bringing me more-or-less back to normal, if a tiny bit "bowlegged".
If I do that, it'll mean the main tube won't be tightened all the way at the top (casquette) end. But, I've read they are not supposed to be super tight anyway, & of course I'll tighten up the lower clamps like crazy.
Does anyone think that would work, or should I just go ahead and pull the tube & get it straightened at a machine shop? I'd rather avoid the trouble of pulling the tube, if possible.
Thanks for all the suggestions!