Lava Cap for 70's "Century" model

My cap broke so I scanned it and used the data to create a new one in CAD.  This cap screws onto the glass threads and uses an o-ring seal.  My o-ring was brittle from age and had some glue stuck to it from a fix attempt.  I replaced it with a 1-1/2" x 1-3/4"x1/8" #81 o-ring (for faucets).  Your original o-ring will work if it is not damaged.  This does not come with a new o-ring,  If you need a replacement o-ring you should be able to find one online.  I used a part number '02-1618P' from larson (purchased on Amazon).  It appears the Greenlee  '51316' is the same size and should also work, but I cannot confirm that.