Hi Colin,
I just had a company stamp me out some fibre washers of different thicknesses for this very situation, though for the alignment of the main bearing oil connections on the crankcase.
These are 1/8″ BSP so depending on the size of your oil tap i can either help you with a selection of 6 thicknesses between 0.8 and 2 mm or i can give you the details of the company so you can get some stamped out to the size you need (though with a minimum order of £18 youll be getting a few made!)
Good luck with the tank removal!
Richard
richard@mossengineering.co.uk
