No names or part numbers. No numbers on the spring

Simonton no longer makes this balance assembly, unfortunately. The good news is that we have a more modern assembly that works just as well, if not better. The video below will go into more detail as to exactly what parts you need to buy and how you can install them.

Also note that since your sash is 14.6 pounds, you'll specifically want one 7.5 pound spring on each side of the window. That should be perfectly sufficient.