1970-1974 andersen window balancer replacement

A home owner from Ridgefield, CT says:
June 22, 2019
I need a replacement for this broken balancer. Beside the A/W manufacturer logo there are stamped this set of letters and numbers: B 4 19 7 70
No stickers or labels on window's frame to identify precisely type or year of manufacture.Double hang window, lower section clear glass approx. w=24"-7/16
H=13"-3/4, upper section the same. The approximate weight of the upper end lower widow pans is 7-8 lbs each. Any help on choosing a proper balancer replacement will be appreciated. Thank You very much, Bob.
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Paul from SWISCO responded:
June 25, 2019

Thank you for reaching out to us, Bob. With an Andersen sash balance stamped "4 19", our 24-431 should work well as a replacement. Look it over and let us know if you have any other questions. 
Andersen Sash Balance, 419, 425, 431
Andersen Sash Balance, 419, 425, 431
24-431
$54.20
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