Time to Add a Hinge
Chris...Ok, we've got the same boat: 1973 Convertible 23. If you want pictures to compare details, let me know.Mine is equipped with a two pin hinge assembly under the mast step you describe. You need to remove the existing oval base, clean off the sealant, and mount the hinge assembly (4 through bolts, fresh 4200) in its place, on top of the compression post through the cabin. The existing oval mast step base is remounted on top of the hinge assembly. Step the mast and put in set screws to fix the mast to the oval step base. You'll have to back off your shroud turnbuckles a bit to allow for the slight added height. Next time you remove the mast, pull the appropriate pin to hinge (I've seen past posts by owners who lower to bow; other who lower to stern). Once down, pull the second pin to remove. The top half of the hinge assembly stays with the mast. The mast is a lot of weight as it gets low, and you need to adopt a lowering method to keep it under control. There is a mast lowering scheme in the archives on this site that I use.D&R Marine lists a mast hinge on the parts sheet for the 23, but no picture. The website given by Bruce, below, has my hinge listed and shown. On Dwyermast, go to Hardware, and you'll find the DH2150 Hinge w/ 3/8" pins. That dimensionally matches the one on my boat. If you want to really get organized, add the Halyard organizer plate DH2890 under the hinge, so you are ready to mount blocks and run the halyards aft for easy sail handling. Hope this helps.