Channel Balancer
John
I will do more research this weekend and get back to you
JUohn
Windows by Acorn per original builder memory. Side by side 36"W x 72' high non tilt. Picture shows a brown plastic (genius design) remnant broken retainer clip in left side channel about 3" from top frame cross member. The original balancers top clip secured here (Slot shows in picture of right side channel) and apparently secured at bottom of channel frame slotted channel frame guide about 1" up from bottom frame cross member. Hope this is sufficient info to get me what I need to get all back to normal operation. Thanks
John

Acorn 3500 non tilt with additional information.
Confirmed the top connector broken piece is remnant of 19-009 and visible glass is 33" high X 31" wide. Side Channel top slot to bottom connection is 32.5" and appears the 15-003 winged connector will work best. I would like to try two of the suggested replacement balancers with 19-009 top and 15-003 bottom, plus the 15-004 spares with pins just in case.
After checking out your comments have confirmed the brown plastic remnant found in the channel slot up top is a 19-009. Checking other answer postings feel confident the 28" Series 385 balance 2740 or 50 is my correct type. Only issue is the weight which is definitely in the range I selected. The bottom connector on this unit is 15-004 winged style that will attach to the bottom cut out of the side channel rails. Top connector 19-009 and winged bottom plus visible glass height of 32.5". I would like to order two with whatever additional components you suggest will get me back in operation, The windows were always hernia creators even when new. Will be needing screens if the plan works.
Thanks for quick response. Please check out the max visible glass height is 32.5 and 35" channel will not fit. I originally told you the windows were 36 X 36 but actually in 33' h by 32" wide range. I do believe the channel should be 28" to allow top clip to insert in the cut out up top and connect to bottom no more than 1" from bottom of the frame? What do you suggest?
John
Can you also confirm the exact weight of the sash?
Clarification - I do not have a balancer only broken brown remnant (picture above) that looks like Acorn 19-009
Leaning toward the 385 since the Top 19-005 appears it will be ok for clip into the slot same as 19-009. The 28" length measure same as space between the top slot and channel indent at bottom to connect with the winged shoe 15-004 better than any of the S710 series. In your opinion will the 19-005 top cause problem since it looks very similar in function? I would like your best suggestion since I am willing to place order and continue quest for right combo. 710 top good, bottom connector needs wings since no other apertures in bottom channel to connect
Lets try the S710/19-009 top with 2840 Option. I will order two and add spare 15-004 winged bottoms since there is no other way the bottom can connect by my inspection of each window channel. Seems like logical place to start. Appreciate your patience and guidance.
John