212 RH one-fifty

Just purchased one with model plate saying "one fifty " instead of "one-thirty" SO I have one of each now. Any one heard of this ? The plate has black background.
I am driving both at the same time with a 210 HD 130 combo ( of course with the built-in 210 disconnected) , external speakers really cut down tube rattling. Very sweet. Now I need to find a real MM head.
Any idea what it is ?

I just picked up a blackplate 212 150. Needed soldering on a board, lots of disturbed joints. Seems all stock. Phasor, but no trem. Faceplate says trem, however. Should I take the wheels off?

Model described above says HD. What does H stand for? Are the earlier ax 27 limiter tube models better?

The HD stands for "Heavy Duty" (MM name for high power, the construction quality is still the same).
The units with the 12AX7 phase splitter sound warmer at overload but are more prone to catastrophic output stage failure if the 12AX7 shorts.
Steve