I can help with that splice depending on when you are down this way. It's also a pretty easy splice to learn if you want to do it yourself.
Splicing Amsteel to Sta-Set
I've dropped the mast on both of my boats for various reasons, and when it's down I use that time to clean and overhaul the sheaves, replacing them if necessary. Does the Ranger 23 have a tabernacle (hinge or pivot) at the base of the mast? If so you could drop it with the help of two (or maybe one) other. That is what we did on the Catalina 25, and it has a 2' taller mast.
Fisheries Supply has most of the Shaeafer and Harken sheaves in stock.
I found this thread on dropping a Ranger 23 mast:
Unstep mast on Ranger 23
Rigrite says you have a Kenyon 3550 mast:
Kenyon 3550 Mast Section
They describe the appropriate sheaves there. If they really are 21/64" wide then using any line over 1/4" (16/64") would cause them to jam, which would suggest doing the amsteel/double braid splice. 1/4" double braid is pretty small for a halyard and won't work too well on most winches.