Southwind ladder mount fastener question

74 Southwind (photo attached). Noticed 2 out of 3 bolts missing from
lowest portside ladder mount. Unsure for how long. I presume these would be ss bolts going through transom with perhaps some backing plate on the inside(?). Or screws going only partway thru? PO had new tank & upholstery done, so have never needed to take rear seatback off. Can anyone tell me how it fastens, what size fasteners, and level of accessibility?

Never noticed excess water in bilge last year, so is it coming in?

Eventually need to replace steps but if its bolts and difficult, I'd like a temporary fix to keep any water out. Maybe insert some particular screws or temporarily plug with silicone?

8122pbrainard wrote: The silicone goes in the trash! I'd go with 4200. Yes, you may have to pull the tank to do a proper job with the fasteners.

Thanks Pete

So it is bolts? So you say as a temporary fix squirt 4200 in the holes to prevent water and later can dig it back out to do permanent fix?

That makes it simpler. Don't "think" it's leaking, would have to take seatback etc off to confirm, but if heads are broken off could/should theoretically confirm with flashlight or probe from the outside. Thanks!