Would this be it?

Product code 170074, 686 Carry Comp. 3" ported barrel with dovetail front sight. 7 shot unfluted cylinder, rubber grips. Also found with a fluted cylinder under same product code.

SCSW 3 ed, Performance Center Models, pg 362-363, Supica and Nahas.

Hope this helps but that was as close as I could find on it.