There is a lead here.
http://www.hayseed.net/~jpk5lad/IC-720/720Index.htm
Can't tell how old it is.

I also have an Icom OPC-137 cable which has the 24-pin connection on
one end, and the output is split into two DIN connectors. One is
7-pin, and other is an 8-pin connector. They were originally intended
to interface the IC-751A to the AH2, 4KL or AT150, but could be used
with many radios with the 24-pin accessory socket. This one is brand
new, and I would be willing to sell it for ($20, what I paid for it)
plus shipping.

Dick - W6CCD
Remove 33 from address
or use my call at arrl.net


On Mon, 22 Dec 2003 18:44:56 +0000, Joe McElvenney
wrote:

Hi,

I'm in need of the type and/or part number for the
subject plug so that I can order one. It is a white nylon,
24-pin affair, with a couple of locating notches and a
chamfered corner. It looks like some kind of auto spare.

If anyone can help me find this, I'd appreciate it. I
have looked in a couple of on-line catalogues but the ones
that have turned up are close but not exactly the same.


73 de Joe, G3LLV