There were two different bearings used in these boats. The traditional cutlass bearing has a brass shell surrounding and supporting the rubber bearing. Some early boats used a bearing whose supporting sleeve was a non metallic composite. The non metallic design is made for boats whose bearing is installed in a stainless steel strut to avoid
galvanic corrosion. This type has proven to be challenging to replace as they tend to disintegrate when you attempt to remove them.
Since none of these Catalinas were ever built with a stainless steel strut, there is no reason to use a bearing with a non metallic shell. Our brass shell bearing will replace a bearing of either design as long as the dimensions are the same. The brass shell has more inherent integrity making it easier to replace when the time comes.
