Using any old electrolytic is a crapshoot. Why would you risk your expensive
power transformer running with original or "recently reformed" old
capacitors?

Burn up a couple of power trannies, as I have done to my dismay, and you
will use only "NEW NEW NEW" electrolytics.

The new caps are cheap and very reliable. And it's not hard to stuff them
into the old containers, as you noted, if you want to preserve the original
appearance. I could teach a 12-year old how to do it in 10 or 15 minutes.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html