Robin. Drill your holes for the fasteners on your deck organizer and stopper then you know the exact thickness. I buy my fasteners long (usually 1.5 inches for a thin fitting) - mount the piece -some have backing plates some do not (sheet stoppers on cabin house top do, winch does) then cut off excess screw with a Dremel and cut-off wheel, finish with a small fine file to prevent scalp and sail lacerations. Most people here on the list will then overdrill the diameters and fill with thickened epoxy, then redrill when cured, bed and mount the fitting. How is that for complicating a simple little thing?!?! LOL. It is a bit of work but it is a well found practice on a cored deck. Maybe we could get a diagram or photo essay up on the MSOG page as a visual aid. Unfortunately I am not drilling any holes in cored areas at this time. If I do, I will photograph the process. Most early model 17's did not have Main halyard winches, but a # 6 aluminum would be a great application, Be sure to offset the winch mount to your stopper fairlead or the line will chafe at the stopper exit. (drum will be mounted inboard of the stopper fairlead if you halyard is on the starboard side of the house). Take Care, Have Fun, Go Sailing GO M-17 # 316a LB/GF! Team Geezer Racing......Old and In the Way In a message dated 7/13/2008 6:34:42 P.M. US Mountain Standard Time, robbin.roddewig@verizon.net writes: I have a deck organizer and line clamp to install on the cabin top of my M-17. Anyone have an estimate of the thickness of the balsa cored cabin top? Another question is about mounting a halyard winch on the cabin top for the main halyard. My 1975 seems to be the rare model that does not have this winch. Any advise on adding the winch? It looks to be the same size as the winches for the jib sheets. Thanks Robbin hull number 056 "My cousin saw a sign that said drink Canada Dry. So he went up there." _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats **************Get the scoop on last night's hottest shows and the live music scene in your area - Check out TourTracker.com! (http://www.tourtracker.com?NCID=aolmus00050000000112)