Need dimensions for S152-7 lb coil please

I need dimensions for your Series 152 - 7 lb coil balance springs please. I need to buy a coil spring of 1/2 inch wide, max diameter of 1-1/4 inches, and with a length of around 30 inches.

My window sash weighs 14 lbs (on bathroom scale) so I want to buy 2 x 7 lb springs (one on each side). My original window springs broke after 20+ years (as shown in the photos) because I think they originally had the wrong weight springs installed. The window erroneously had 2 x 12 lb balance springs installed (i.e. 24 lbs springs for a 14 lb sash), which I think explains why it was always stubborn and difficult to move. The old coil springs were a double spring set, and always stuck and ended up bending and breaking as we fought to open and close the window. So I want to try 2 x 7 lb coil springs and need to know if yours are the right dimensions please & thank-you!

Hi, here is a picture of the original pivot shoe. It doesn't have any identifying marks on it, so not sure this is gonna help much. The coil springs attach to it by a single screw near the top right side. I was thinking to buy the S152 coil balance because its screw hole and end tab closely resemble the old coil spring (to my eye anyway).

The windows were originally sourced 23 years ago from a local Hamilton company called "Award Windows" and of course we called them for service but they claim they didn't manufacture the original windows and the company that made them is out of business; also they wanted $500 to come and replace the failed coil spring(s). So I'm good paying for two new S152-7's, if of course, you think these might fit. The 40-inch coil travel would work. Also please confirm the S152-7 coil balance has a maximum diameter of 1 1/4 inches?
Thank-you!