Here is a picture showing the insides of the ITT Model 13 that was given to me by LCEC. I rewired this cobrahead with a 70 watt HPS ballast that I removed from a Cooper Lighting 70 watt HPS barn light.
Unfortunately, I have a couple of fixtures in my collection where using wirecaps WITH tape became necessary. In both cases, I also ran pigtails to the terminal blocks.
I plugged it in with the old ballst installed when i first got it and after a second or two, the lamp flashed once or twice and then nothing after that.
I wish more fixtures were like my M-400 and OV-10, having a long terminal blcok for all of the fixture connections instead of just one for the feeding leads.