Modern Vespa

The washer should have slight bevel on one side which goes towards the step/shoulder on the shaft, The bevel accommodates the tiny fillet or or radius where the step meets the shaft. A hard corner there could be a liabilty.

The BGM washer has that and I put it with the bevel facing the step but it still didn't bring the clutch down enough

Your engine takes a thin washer like the one that broke, the 3.x is too thick...

Do you mean the seal ? Where something has been rubbing against it ?

Latest the problem is resolved as expected the clutch thrust washer had broken and was eaten by the gears small metal particles and a silver sheen in recently replaced gear oil
I took 1mm off the new 3.45mm so it's now 2.5mm allowing the clutch retaining nut to almost fully go on I have fitted a 2mm clutch cover spacer
And the good news is it goes into gear with the clutch working as it should
I've not split the case yet but done 2 gear oil flushes and also flushed with petrol now a 3rd fill of oil I'm going to take it round the block tomorrow see if it goes into all the gears smoothly and without any terrible noises then I will give it another oil change.

Congratulations ! Happy New Year !

Maybe the washer was not oriented correctly ?

Think I still better split the case and see how it looks inside probably going to have to atlest change the bearings

Never split a case before do I need to take the engine off the scooter?
What parts gasket etc do I need to order which bearings also
Any advice welcome 🙏

Splitting the case will go a lot better with the engine on the bench, especially if it is your first time and you are doing some diagnosticating. Removing and reinstalling an engine is one of those Vespa 101 skills.