Gas Tank Gauge & Cap for Series 33?

At the St.Louis meet someone was showing a reproduced tank gauge for I recall the series 80, which looked like it might replace the unit for a Series 33. I would like to pick back up on the lost connection to see if these are still available, and what size/threads fit the Series 80, and if by any chance this would be the same as for the Series 33.

I also would love to find a good gas tank cap for the Series 33, which included the slightly flexible internal cover that screwed down with the large thumb-screw to form a pressure tight seal. Mine lacks this internal seal plate.

Thanks

Dave Barclay

Dave Barclay