[Tigers] Tach / Speedo parts

[Rollright at aol.com]

Hello,
 
I'm nearly finished the Auto Meter tach project
 
1. take it apart
2. hog out the I.D. to accommodate the Sunbeam inner bezel
3. cut down the tach can rim diameter a bit
4. cut in the tabs into the tach can rim
5. paint the inside section blue
 
Here is where I got stuck. 
 
You know the rubber ring that goes between the glass and the lower black  
inner bezel?  I don't have one.
 
Anybody got any idea on where to get them?
 
Help!
 
Jim  Armstrong
Mk 1A 382002083
LRXFE