Does anyone know what happened to SUMO Electronics?

JD, am I understanding that you are after an Electra Schematic? I'm not sure, but I may have one.  Please confirm before I go crazy looking. 

Here you go,  this should help. 

http://www.davidsaudio.com/Electra.pdf

Thank you timlub!

This will go a long way to helping me repair the pre amp.
I was correct, I only had half of it.

Thanks again for filling in the the other half!

JD

The Charlie tuner I had was made by Sumo.

JD,   one of my best friends still uses an Electra.  He has made a ton of cap improvements on this pre and it responded incredibly to the changes.  This pre already uses 1% metal film resistors, but it is full of sub par caps. so if you figure out the repair, do yourself a favor and replace the electrolytic and ceramic caps while you are in there. 
This old pre gets shockingly good.