Replacement for sash balance 27 4 CP CALDWELL

A quick learner from Bakersfield, Ca says:
My windows utilize the Caldwell Sash Balance System and I need to replace some of them. Printed on the metal channel is "27 4 CP CALDWELL". There does not appear to be a series stamp located on the channel for further identification. The balance is 1/2" (9/16") and appears to be either the series 380 or 385...I cannot tell any difference in the bottom shoes between the two balances so I've attached a few picturees for your assistance. Thanks, Mark
A customer submitted photo of channel balance attachments.
Profile picture of Paul
Paul from SWISCO responded:
Thanks for posting, Mark. I agree with you: this channel balance is either a Series 380 or a Series 385. Take a look at our 15-005 and 15-004, the respective shoes for those two Series, and compare their dimensions to your own shoe. Is the depth of your shoe 1-3/32", or 1"? Keep in mind that while a fraction of an inch difference may not seem like much, it is important to the function of the balance. I recommend you get as close a measurement as possible. Let me know what you come up with, and we can work from there!
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