Joe, the 90-14 is probably the size of the needle. ... you know, for heavy or thin fabrics. A 60-8 is for light weight fabrics. 120-19 is for the heaviest fabrics. 90-14 is medium.... good for cotton quilting fabric. Look at the needle to see if there is a flat side to the shank. Standard needles now have the flat side. I'd use a modern needle to determine the length... I think 15x1 refers to the length of the needle.
You probably know all this but hope my basic knowledge has helped some.