Pintle Mount Shock

I have been a bit time poor for the past few weeks - that should change near Christmas, but I managed to get my phone (camera) into the buoyancy chambers that have the top pintle mount backing plates in them.
Oh dear...

The port side

The starboard side

Pine!!! He almost missed the backing plate too...

I removed the bolts (and pintle) from the starboard side (I can't do the port without someone to hold the spanner) and tried to move the pine but it is solidly glued (epoxied) on. I haven't tried REALLY hard to move it yet - I'm trying to get advise on this. At this point I think the path of least damage is to retain the pine. This area is well above the waterline with the floor that you can see on the same level as the cockpit floor - probably 600mm above the water. The hull-beds are below this chamber so it should never see water - pine should be OK - yes?

Keep in mind that I can't see what I'm doing  - the pictures make it look simple to get access but that is via a 6" round access hatch (port side shown below). It'll be "feel your way".

My plan for the starboard side is to place another piece of 50mm x 19mm pine with and 'L' shape cut out of it around the corner near the bolts and (Bote-cote with thickener) glue it to the existing pine and the transom. The reason I'll use more pine is to keep the "squashability" the same.
Then I'll coat the whole lot on port and starboard with thinned epoxy (I'll pre-coat my new piece too).

I will fill and seal the inner two bolt holes then, when I refit the pintles, I will only use the two outside bolts with oversize washers that will span the existing and new parts of the backing plate. I'm reasoning here that two 1/4" Stainless Steel bolts are strong enough for one 8mm pintle mount.