Gould TC20 counter info

[Big JJ]

Hi
Quite new to the forum but not to repairing test equipment. Used to work for Wayne Kerr in Bognor building and fixing stuff.

I have a number of Gould bits of kit which I have had to decades, since last century!!!! Been fixing the scopes for years, Telequipment and Gould.
My TC 20 counter has been stored up for a while during a move, got it out to check it over and it does not work.
 I am not sure if I ever had the manual but cannot find it now anyway. It has never gone wrong before!!!

Have spent hours going through the sites listed without success  , found a slightly early model but many differences.
Gould usually provide good info for their kit
So if anyone can help with any info on a GOULD TC20, that would be appreciated