Ed, I think the card you are thinking of is the WECO 451 card. It's a 40 pin, 4 inch card that supports 7 CO lines. It has 20 pins front, and 20 pins back. Many are vacant, but it has tip & ring on the CO side of the line cards going in, and tip & ring on the station side of the line cards going in. As I recall, the ring sides are just strapped together on the card and the tip sides go across the isolation transformers. I figured this out when I was in a pinch and needed to get music on to an ITT 400E card. I took the two tip leads from an unused set and connected them to the MOH inputs on the 400E and I had music on hold. I had a 400D card go belly up on me and I didn't have a spare one around that I had modified for bridged ringing. I still can't figure out which component failed on that 400D. I had a 400E die on me and I tracked it to a bad diode. A simple swap and that card was back in action. When I get some time I'll give that dead 400D a good look. I take great pleasure in resurrecting dead electronics.