I think you can get them from Neal (Here), CRX (Here), or anywhere else that sells glow gaskets for 20mm Carlco triples.
Alternatively you could make one yourself using these instructions: DIY Glow Gaskets for Triples and Other Glow Stuff
I think you can get them from Neal (Here), CRX (Here), or anywhere else that sells glow gaskets for 20mm Carlco triples.
Alternatively you could make one yourself using these instructions: DIY Glow Gaskets for Triples and Other Glow Stuff