Looks like a well supported set up. If you drive very far you may get wear on the floor where the small center support contacts the boat bottom. I had to put two small padded rails on my trailer to support the bow without getting chafing. Just a suggestion.
While your working on your trailer replace those corroded u bolts and nuts before one breaks! I splurged on stainless parts for my trailer. I've seen too many trailers on the side of the road.
Sure wish my sib was nice and new. Dang, That looks good.