I'm just about to kick off a TOS era campaign set on a Hermes class scout and i'm looking for an adversary ship, which will probably be around on a recurring basis.
Anyone got any suggestions for a Klingon vessel of the TOS era which might provide a credible threat but without outgunning the Hermes by too great a margin ? I've ruled out the D7 as being too powerful, and I may come up with an original design but I thought i'd fish around for some suggestions first.