16 5 GP Caldwellb
A handy person from Kailua Kona, Hawaii says:
August 23, 2016
Part number on side says 16 5 GP Caldwellb. The sash device broke and I need to replace it. The metal slide measures 16-15/16ths.
Tom from SWISCO responded:
August 25, 2016
Please see our S385-17, this looks like it could match your hardware.