I had my bearing replaced last summer, by my local shipwright, who told me that there are at least two, if not more sizes of lower bearings used in the B37, even in the same year model.
The ship wright had had some stainless steel housings made, with a not expansive inserts, which he had modelled on a previous B37, but they did not fit my B37. I would liked to have used the Stainless ones, but we replaced them with the alloy ones, as the boat was on the hard, and we had no time to wait for machining.