Backing plate support for rail mount and back stay

[Riga]

I notice some cracking in the fiberglass around where the stern rail mounts to the boat as well as around where the back stays (split back stay on my boat) mounts to the boat. I think the backing plate are shot. These appear to be made out of marine plywood and probably never replaced. Does anyone know about this? I think these supports are suppose to distribute the load. I wasn't sure if I should cut a similar size block out of marine plywood, teak or another hardwood like oak. Any help would be greatly appreciated.

 

[emergpa1]

Riga,
I think that backing plates made from oak plank, if sealed with a few coats of sealer should serve well for several years, and be alot cheaper than having metal ones created.
Keith