Nice key work. A pleasure to work with. This takes 9.5mm pads on the upper joint.
Bore: Serial #181585 is around 15.1mm or even 15.2. Probably Selmer was catering to jazz players at that time.
Serial #91970 has a 14.9mm bore.
#219571 Bore top LH, 14.95, bottom of LH, 14.55. So this new of a model 100 has a poly-cylindrical bore!
James Gray says he has found one that is 15.1mm at the top of the LH joint and 14.5 at the bottom.
The newer Signet 100s seem to be designed to use a fairly long 66.8 or 66.4mm barrel.
#91970 is reasonably well in tune when pulled out 1.5mm and using a barrel ring. Without the ring, the throat tones become too flat. With how most groups play sharper than A-440 pitch, #181585 will be considered in tune. The player will need to lip up on some throat tones when they are played loudly, and might not be able to play them as loudly as he wishes if they are sustained. I was unable to see if a tuning barrel would work well with #181585 to even out the intonation. My barrels have a smaller bore size, so didn't work well on that horn.
Newer models are better! #91970 has a lot better intonation, the high register is significantly better with the 1990, #219571.
Because of the big bore, the horn plays freely and has a big sound! That's one reason I feel that this would be a good instrument for a student, beginner to intermediate. Students majoring in clarinet in college will want a better instrument. Well regulated Signets are a joy to play. The sharpness in the upper register can be lipped down.
Phil's Signet 100 Reconditioning:
Serial #181585, perhaps made around 1979-81.
26Jul08 #91970, perhaps 1973-74.
2Aug09 #241765, perhaps 1994.
Mar2010, #171880, probably made in early 1980s.
Mid-2010, #219571, perhaps made in 1990. Bore top LH, 14.95, bottom of LH, 14.55.
August 2010, #x12054 or possibly 142054/192054. This clarinet has two bands on the top joint, one at the very top and one under the top trill key. The banding obliterated the real serial numbers, and there are scratched numbers on the bottom of the LH joint.
I have only found serial number information at ClarinetPerfection.com for the Signets.
This info from John A might be helpful:
#211068. Signet 100 with original case. An original pamphlet on care of grenadilla clarinets in the case has a reprint date of 5/79.
#111468, Signet 100. Thanks to Cindy S for passing on this information!