skiando has put many scans of Selkirk catalogues
online - are a bit cumbersome to search for a specific weight.
I am right now in the process of compiling images for the Selkirk catalogue on Scotland's Glass - have scanned all Selkirk (printed) catalogues for that purpose: cannot find your weight - it is definitely not in the 1990 catalogue.
Consequently most likely made in small numbers only, possibly a one-off, and as it doesn't show up in catalogues I would be very pleased if I were allowed to use your image ... even better, if you could also supply me with a few additional views, including the base.