Hey Robbin, I think you should query the master Jerry M about the bulkhead/compression post/support issue. It seems to me that the mast and tabernacle would have some sort of support underneath the coachroof. As you know, my M23 was modified when I acquired her. The area underneath the tabernacle had been rebuilt, the area moved a few inches, and a metal plate added below at the top of the bulkhead compression post "boards". (re: those pics I sent). I wonder if perhaps your standing rigging had been over tightened at some point in time. Anyway, whatever core material you choose to employ, it will be better than what you removed! Keep the faith, you'll be on the water soon (LIKE ME). Bones ____________________________________________________________ The #1 Worst Carb Ever? Click to Learn #1 Carb that Kills Your Blood Sugar (Don't Eat This!) http://thirdpartyoffers.juno.com/TGL3141/534ca67e694d1267e6c33st02vuc