I dug through my notes and I have the metal front tank for the 150-250 amps as being a 4BB2C1D. So as best as I can tell, you need need a 4BB2C1B for your amps.
The only difference is the last letter that represents how the tank is meant to be mounted. D is for vertical mounting and the B is for horizontal.
Before anything else, you should check the tank that you have and see if it is the original tank or if it has been replaced. If it has been replaced, it may not be the right one and it may be the cause of your bad reverb sound.
Look at the tank and see if there is a code number rubber stamped on the case. If not we can tell you if the tank is original or not by the physical and electrical characteristics. Do you have an ohm meter?