At $60.00 for the chassis you can't argue - worth a shot.
I'll be getting the trannies from Brian Wallace at Marstran - he's been knocking up some dual OT JTM45/100s himself by all accounts.
His PT has a two taps, one to get a B+ around 560v and another for 490v. As he rightly points out, modern KT66s will be running for their lives with 560v.
You never know, I might even be able to get one of those swanky PT's Drake wound for the Marshall JTM45/100s. You never know unless you ask, might just get someone new that doesn't know they're not supposed to sell those except for repairs (lmao).