Model 18 Primary Chain Case

I would sugest "mice" have had a nibble.

Dont know if its the correct part,but the  case looks unusually straight.  I would not write it off as the bit that actually seals looks ok.

I would not have thought that many people will be laying on the ground to see your unusual "scallops" but on reflection I was once at a posh Italian show surounded by Million pound Ferraris with my little Ducati M3 and  was pounced on by a glamorous mini skirted lady photogropher who spent 15mins rolling on the floor under my bike trying to snap all angles. Sparked me up no end!!.

I'm fairly sure your outer primary case is correct - I have a '47 Model 18, which has what seems to be an identical outer primary case. I can't guarantee it's original, but from the history of the bike, I believe so.

Hope these pics help,

Alan

The attachment may be of some help. It is pre-war but the chances are that little had changed 10 years later.    The numbers are......

3653 - Inner Chaincase      Models 1, 16H 18, 19, 20, 50  & 55

3654 - Inner Chaincase      Model 18

3413 - Outer Case/Cover   Models 1, 16H 18, 19, 20, 50  & 55

3414 - Outer Case/Cover   Model 18

Other number relate to Models CJ, CS1, 30, 40 etc.