Grabbed my vernier caliper and processed the dimensions into this image:

 

Is the black ring rubber? Is it part of the housing or the fuel gauge?

 

It isn't rubber but SS...I guess it's part of the fuel gauge.

To be sure, I would have to check out by dismounting the chrome ring. If I have some time tomorrow (or any other day), I will take off the ring and make some more images for you, OK?

 

That would be above and beyond, so don't worry if you don't have time, the part is only 20.00 from Zanotti with shipping. I think I will just go ahead and order it.
Thanks Rene, very helpful

Actually Zanotti wanted 11.00 for shipping Total 28.00, Chicago HD was less.

 

Rich,

I checked my parts catalog; when you take a close look at the image below, you'll notice the SS ring is a part of the fuel gauge (18, 19). The chrome ring's (6) inner diameter is 2 1/16"....

 

Thanks Rene