Well, I've been looking at the FASA klingon SRm to see what hasn't been fleshed out yet and chanced upon the gunboats. The fact that Owen has deckplans for this little beauty doesn't hurt either.
K-4 raDwi Class Corvette
PRODUCTION DATA
Origin: Klingon Empire
Class and Type: K-4 raDwI'-Class Corvette
Year Commissioned: 2256, Cloak Refit 2275
Designed to fill the need for a anti-piracy role, the K-4 was put into service in early 2256. Equipped with a top mounted docking clamp, the K-4 would “latch” onto suspect vessels and the 6 marines carried would then board the attached ship. Not being intended for frontline combat duty the raDwI' was only equipped with disrupters, meaning if used in any major fleet combat, they would be at a severe disadvantage.
The only known variant is the one used by House Ch’Kor. Their house is quite small and is unable to field anything larger than a K’Vort Class Light Cruiser. They have taken to installing a KP-5a torpedo launcher, which gives this little ship some big teeth. The KP-5a is a house weapon specifically developed for small attack vessels. (Space 4, Offence Value 5, Minimum Size 2) Most houses consider mounting torpedo’s on this class a colossal waste of material, but they still keep an eye on this variant incase some day they have need of it.
Following the technology exchange with the Romulans, the K-4 was equipped with cloaking devices allowing it to slip undetected onto a enemy hull and offload it’s troops. This greatly increased their survival rates and crew morale on these vessels rose sharply thereafter.