A perplexing puzzle: National NC-183D power transformer

[Electronic M]

IIRC the LM317/LM337 family of regulators can drop 40V (input to output) a chip and source an amp of current. Three such regulators in series could comfortably drop 100V no problem...Plus they would reduce B+ hum to well below spec, and give you rock stable B+. If I were doing this I'd only drop ~20v in the first reg so if before warmup the B+ goes high without load there is safe headroom.