If the original chain plates only attached to the deck, then the bulkhead may not be structural, but the boat can't be all that big, and is poorly designed IMHO. If the chain plates had been attached to the bulkhead by the manufacturer, they would have to be structural. It is a pretty stupid idea to attach chainplates to the "lid" of a box rather than the bottom of the box. If there's a problem with the hull-deck join, the chainplates fail by default.
I'd note that you never said the chainplates had been modified and that the attachment to the bulkhead was done by the previous owner. Having chainplates attached to a bulkhead is a pretty standard thing and it is very unusual to have them only attached to the cabintop. Must be a pretty small POS boat to have them that way.
I confirmed with the group that the bulkheads were never glassed in only screwed in like I said. But the headboard attached to the horizontal compression post and the original chainplates attached to part of the headboard/compression post and part of the bulkhead. Its a Coronado 25 KIT boat that was built for racing from the start nothing special by most peoples standards. allot of modifications were put into it its been down the west coast and back a few times. I think it went to Hawaii which is where i wanna take it.