**Condition Notes

This is a unique vintage mouthpiece from the 1970s-1980s. The etching on the table says "OCB-91" and possibly "5". The brass end cap on the mouthpiece is tarnishing and the cork is damaged. The glass is cloudy in some areas and there are some scuffs. The mouthpiece does not include the original packaging. Unfortunately, we are unable to measure the tip opening. We found a size chart on a forum, please view below. Please view all photos for condition. 

Sizes:                                                            Tip Opening:

No 1	Very short, Close
No 2	Medium, French
No *	1.00mm Very Popular
No 2*	More open than OB*
No 3	1.16mm
No 3*
No 4	1.19mm
No 4*
No 5	1.25mm
No 5*	the most open

OCB stood for “Off Center Bore”. These models were popular with jazz and
classical clarinetists during the 1950s through the 1980s. O’Brien is said
to have put really good facings on his mouthpieces. In general it’s thought that O’Brien has been underrated as an artists just because of his status as a
manufacturer and retailer. Tony Scott (pictured below) played a crystal
mouthpiece during his jazz recordings years in the 1950s and 1960s. The
OB* was described as a “medium” and his most popular facing.

More about O'Brien:

O’Brien originally made the Selmer Clarion crystal mouthpieces. Identified by
only a couple of flutes (indentations on the side of the mouthpiece).

The O’Brien mouthpieces quality varied over the years. In the early
1980s a cousin of the original O’Brien created mouthpieces from time to time.
These mpcs were not considered the “prime” mpcs

Earlier mpcs the glass could be slightly darker, even slightly pink. On
many of these models their would be a date etched on the glass. The
original mpcs from the early 1940s, made by the Harry O’Brien, were less clear
and had more air bubbles. So I guess the more “pure” the crystal in the
mpc the less desireable they are.

There was also a mold change in the 1950s as the original mold was broken.
The older mold had 3 grooves on each side (6 total). The newer 1960’s mold had 1
groove on each side. The original Harry O’Brien (passed away in the 1950s)
and he also manufactured clarinets. The son continued to make Selmer Primer
clarinets in the 1940s as the father stopped. Pete Fountain apparently
used these clarinets along with the mouthpieces. (thanks for this
information goes to Michael E Obrien, grandson of Harry O'Brien - if you
read this please email me, your address changed)