As a matter of interest the rear stand is particular to the B30, the B29s having a cast not tubular stand..I was lucky enough to have access to a stand off another B30 to take measurements, enabling me to make a replica for mine..Just one of the B30 parts that is completely unavailable generally...There were three different versions of the B30 engine, each of which had particular differences even though the general layout was very similar...
I have copies of the drawings for two of the engine types and a full size ex factory drawing of the other...I also have some B30 parts lists on file and a lot of other information...Ian
