The information on numbering can be found in the Swedish glass production catalogues book (Ricke) which is out of print and near impossible to find. I had to abbreviate the information on StrÃ¶mbergshyttan to fit the book, so I only included the major codes (Blomvase, dish, ashtray etc) and concentrated the item numbers in 10 year groups. That way you'd get at least a time frame when design numbers were issued, and in combination with the information on designers you could get a fairly accurate approximation. But if you want to get to the bottom of the matter, there is no substitute for the production catalogues.
I also reached a point where I had to decide "yes but WHY would anyone want this information"? These are minor production designs, I think "StrÃ¶mberg 1960s designed by Strand" would be perfectly adequate - the further information that it has made e.g. in the first quarter of 1963 as an olive dish would not greatly enhance the product.