[Amps] Drake L4 preventative maintenance

[mike stokes]

I bought a Drake L4 years ago. This a L4 that was supposedly converted to a
L4B.  Has been a good amp and has made a lot of QSOs.  A few years ago
the filament xfmr developed a bad hum/vibration.  I replaced with one from
Peter Dahl and all is good.

No current problems but was wondering if I should rebuild the P/S.  I am
pretty sure it has original caps, etc.

Also any recommended mods that should be done.

Thanks in advance.

Mike
KK9V