Hi Sal --
Your board was made and marketed by Purist Audio Design in Clute Texas (near Lake Jackson), about 25 miles from Houston, Texas. There was an issue of Glass Audio (early 90's) were Roy Mottram reviewed the replacement boards that were available at the time. The PAD 70 was one of them.
I bought 2 of the boards for the ST70's that I had and installed them, I thought that they sounded very clean and nice. The version of the boards that I bought used a 12AX7 for each channel, not the 12BH7.
Oh, the Pad Board does not use the Negative Feedback from the Output Xformer.
I have documentation for my version of the board if that would help?
Schematic and Bottom Traces and hookup points.
If you have a fax, I can fax the sheets to you.
Let me know,