Still have not received a response

I see Tom responded to you here; sorry if you did not get the message. This shoe looks like our 15-228, which uses either our Series 160 1/2" thick Coil Balances or our Series 165 3/8" thick balances. Measure the thickness of your old coil springs to confirm which you need. I am afraid those stamp codes may not be reliable. The best way to know what spring weights you need is to obtain the exact weight of the window sash. Give us that exact weight and we will work out what you need. 

See our S165-5 5 lb coil springs, which are 3/8" thick. If the window weighs 40 lbs, I'd have (4) of these coils on both sides of the sash, using our 15-206 quad support. That equals 20 lbs of support on both sides of the sash, for a total of 40 lbs overall--being within 1 lb of the exact sash weight should work just fine. Let me know if you have any other questions. 

This video below shows how to install a triple coil support system. You'll be installing a quad support to both sides, but the principles are essentially the same.