Thanks to Jim for the images and information on this wonderful clarinet. From information from Jim, this C clarinet plays well in tune.
Here we have a very interesting simple system LP (Low Pitch) C clarinet. Made of tight-grained and dense grenadilla, it was probably made in former Czechoslovakia if the mouthpiece’s markings are any indication.
An interesting feature is the seemingly original mouthpiece, marked “Josef Kolar/Kladno”. Information for Mr. Kolar can be found here: https://en.m.wikipedia.org/wiki/Josef_Ji%C5%99%C3%AD_Kol%C3%A1r
The mouthpiece is actually an Eb clarinet piece. C clarinets vary in what kind of mouthpieces they can accommodate – some take Bb and some take Eb.
The clarinet features pins instead of actual screws – making this quite an early clarinet, dating possibly to the 1850s.
The added left hand pinky key is an alternate actuator for the top right hand pinky roller key, a quite rare and unique addition. So although this clarinet is definitely considered a simple system, it does have an “advanced” feature.
Measurements of the instrument as follows: