physical differences in 35A and 35M dynamos?

[David.H]

On all mine there is  a "D" or "F" or "SH" on the bakelite(?) terminal block.  Paint and/or gunge has to be cleaned off and the moulded or impressed letter can be hard to see I am always nervous whether the right wire has come up out of the guts of the dynamo....I think  the connection to "D" is the thicker one..... unless they appear both the same gauge wire!