Is there a chance you actually do have a 4 tap cold plate and that aluminum block is just a universal blank that's drilled and stuffed to match what's inside the plate?
It looks like there are bosses that have to be installed and it isn't obvious from that picture how that happens - they may be threaded but more likely they are pressed in place...
It could be a universal mold. I drilled a hole in the #6 spot and couldn't find any porting or anything. If there was lines there, I was going to press/epoxy the threading into place. Guess I'll just hook up the four taps.
That sounds about right.
They have stainless lines, going back and forth (like floor heating) with end adapters. That labyrinth is then cast into a universal aluminum alloy mold.