Mizzenmast

Has anyone in the group lifted the deck plate under their mizzenmast?  The one with the 6 screws/bolts (see photo).
We can see the screws/bolts from above, but see nothing from below.
would like to have an idea of what the construction is before we start getting in there.
We were built 1979 in Canada.
Thank you,
Debi S, Serenity, Hull 110 

I took mine off a couple years ago to strengthen the area. Mine was the same construction as the rest of the deck except the core was a solid wood instead of balsa. The screws you see are just threaded into the deck.

I replaced the core with solid glass then added another layer of 3/8" FRP over everything, then reinstalled the plate and mast step. Masts aren't back up yet so can't say if it changed anything.

Sorry I don't have more pictures. I'm terrible at documenting as I go.

Opened up the deck to remove old core
 

Repaired and painted, hardware is loosely installed so I can mask off for non-skid
 

Scott
Joie de Vivre 1976, #88

We found exactly what you had. The six bolts (3/8” x 1”) were threaded into a block of wood. Stainless bolts securing an aluminum plate of course melded together over time. A few days of dripping muratic acid around the bolts finally released them. Now to replace the wood underneath.
Thank you for responding to my question.