As I mentioned much earlier in this thread, early 200A's did not have the protection circuit that would use those missing diodes. So at least now we know that yours is an early 200A without it. And a couple of months could be a lifetime in terms of production changes.
Yes, the bias voltage is about 1.3 volts rounded up. I would like to see that up a little higher, just to see if that cleans up the distortion.