[Boatanchors] Seeking Lambda Model 50 tube-type powersupply manual or schematic

[Ed Sawyer]

hi Folks-

I snagged a nice pair of Lambda model 50 power supplies @ a swap meet this
a.m., which are adjustable 0-500v @ 500ma tube-type supplies.  They will
need some refurbishing, though the major parts seem to be in good order.
Also, I will need a dozen 6L6 tubes as they are missing those... are modern
ones ok for this service? (e.g. Chinese, Russian) Hopefully so.

Does anyone have manuals or schematics for this unit? The functionality of
using them seems pretty straightforward, but a schematic would be helpful
for the task of refurbishment.  I'll pay for copying and mailing costs of
course, or an electronic version (PDF) would be great too.  A search on
Google didnt' turn up anything useful, alas.

thanks in advance for any assistance!

-Ed