st70 power transformer question

Hi everyone. I'm in the process of rebuilding an st70 with the vta board and I ran into a little snag. Every manual or document I have found says that there is the red/black wire from the transformer that I believe goes to the vta board. I remember it being negative voltage, -50 I think. Anyway, my transformer doesn't have a red/blk wire. The one leftover wire is blk and yellow, or brown, it is hard to tell. By the length and curves in the wire it looks like it went to the selenium rectifier. I should have taken pictures before I started I know.

I am about 95% sure this is the wire that should be the red/blk one, but I wanted to see if I could get an affirmative nod from someone who knows for sure. It will put my mind at ease as I hope to fire it up tonight.

Thanks.

Thanks.

I'll do that.

I'm pretty certain now though, I found a picture on the web that seems to have the same cloth lead. But I'll do the test anyway.