The pictures help (thanks) and that appears to be a workable unit for fresh water and in great shape! And could always have it coated to make it last even longer...
What I would do is...
1. Ensure that the bunks are going past the stern so the transom is fully support.
2. Along these same lines make sure the wench stand meets the the bow and usually they are mounted with bolts so they can slide some.
3. Remove the slide offs on the present bunks (they need to be totally flat) so the load is spread out across the entire bunk.
4. Add two extra bunks to help support that non-fiberglass hull even more like the factory designed.
5. And just to help keep the bearings in good shape and it ride / roll smoother, make sure all three tires are balanced.
Hope this helps, and you can find more ideas on the links on the last posting for possible upgrades to use on this one
Enjoy!
Dave