Hi I have just ordered another batch of air filters from RAMAIR and they now stock the Silk size as a standard off the shelf item. These are the best type to fit and I have found give the best all round running and best surface area compared to the cone type which I have found restrict performance.
Just ordered one and then checked my 38mm carb and it’s 62mm (late Mk2 with PG porting) not 58mm so have changed it to a MR-011 which is 17mm shorter in length at 100mm. My original filter is 130mm long but Ramair only do one length.
Ah yes absolutely mine was for a 34mm MKII the filter is spot on. I think it eorks for the 36mm too but I have not been in my shed for a while as had a couple of operations. On the mend now.