There are two separate problems for the identification of Selkirk weights:
1. Most weights are just marked "Selkirk" (no name).
2. The marked year is not the year of first issue, but year of production: I have a large number of Selkirk weights (or at least images of them) with marked years several years after the particular weight showed up last in the catalogues.
Solution: look through the catalogues, starting with the indicated year, and go backwards in time.
Right now I am preparing images for a Selkirk catalogue on Scotland's Glass: for that I have digitized/compiled all catalogues 1985 and later (plus a few before). If you send me images of your weights, I'll have a look.
SMALLPRINT (especially for all other readers): for all images sent for identification, I assume implicit permission to use the images for our catalogue