help needed with Engine ID

[johnnyXS]

i bought a used series 2 engine last year which I'm currently rebuilding. I looking for a potential replacement crank as the existing bigend bearing is shot but having difficulty in establishing which cranks will fit my case.
The case number is 150Li * 796757 and when I check the various lambretta records it suggests that the cranckcase is a 125cc series 2 ?

I have checked Sticky's manual and the early Series 1 cranks had 25mm dia bearing journals both sides but there is no mention if the early series 2 also had 25mm dia journals both sides .

Ass far as I can see I will need to replace the crank with another series 1 crankshaft unless I change the mag housing to the series 2/3 which has the larger mag bearing OD...... but then do series 2/3 cranks have a 25mm mag side journal and bearing ID ?

grrrrrrr

[johnnyXS]

is this a series 1 Crank or is it a series 2 crank?

Does anyone know ?

The mag housing looks like a series 1 from the crank side with the bearing lubrication slot but a series 2 from the stator side with the double dust rim ?....