Here are updated images of the 4 main older Klingon Ships. These come from "Enterprise".
Early Klingon Bird of Prey
There are two more ships to come. The Klingon D-6, which is the mainstay of the Klingon fleet in 2245, and the Klingon D-7, which is the dreadnaught that is just coming off the line and which the Klingons hope will tip the balance of the war. (The Constitution class is the Federation answer to the D-7 an dthere is an arms race to get each ship to the fight).