Fixing/Correcting chain line with spacers
 

Hi,
have re-built a classic early 80's track bike (Reynolds tubing) with mint original paint job including hand painted logos. The only issue I have now is a chainline out by approx 3-4mm. to correct the chainline I need to put a spacer between the sprocket carrier and the hub.
Can anyone tell me where I can source such a spacer. needs to be quality threading etc...

Thanks in advance.

Espresso