Hi, I have a problem with the shroud attachments on my boat and I'm looking for some suggestions/opinions.

I have a Sonata 6, but it doesn't have the original rig as far as I can tell. The original looks like a mast head rig with shrouds terminating at chainplates attached to the cabin. At some point in the past this has been changed to a slightly bigger fractional rig with upper and lower shrouds that terminate at saddles through bolted on the deck (one for each shroud). The deck is plywood cored fibreglass. There is a stainless backing plate of about 75x120 on either side of the deck.

The problem is that the bigger rig has additional loads and attaches at a point that was not originally intended, using hardware that I feel is not adequate. A while ago I noticed some cracks on the topside of the deck around the plate, probably caused by the extra load from the cap shrouds. To take some of the extra load I fitted an additional saddle on the underside of the deck on the same bolts as the topside saddle. I then attached a turnbuckle and ran this down to a steel bar running between two buttress pieces on the hull. This allowed me to tighten down the turnbuckle and spread some load to the hull.

I now want to upgrade this arrangement and replace the saddles with some proper chainplates. These will need to pass through the deck if they are to stay in line with the end of the spreaders. If I do this, what do I attach them to? They will be about 80mm from the hull and there is no bulkhead available. Would I be able to put a spacer, like a block of wood, between the chainplates and the hull?