The thing to consider is the rig. The mast brings a downward force in the center. The shrouds bring an upward force by the hull. This tends to bend the hull up, and to compress the deck and bend it down in the center. I suppose your mast is on deck but supported underneath, since that is the most common arrangement.
Judging from the above photo, the risk seems to be that the deck buckles, if it is not strong enough. Perhaps delamination of the core can result. That's what I think happened in my boat, since the port side (right below) is much weaker structurally than the starboard side.
On the other hand, there is a hint that he left some support under the deck. If so, that might be enough.
Suggestion: Measure some distances with the rig loose. Vertical, diagonal, etc. Then tighten the rig to specs (some 20% on the shrouds) and measure again. If the starboard side is much different than the port side, you may have to do something about it.
On the lighter side, you decoration (plants!?!) suggest that you may not be sailing the roaring forties with her exactly