Dear Friend
l will be very grateful if someone can point to doc which will help me achieve the following.
To be able to use ospf between Router G and both router p and Router H .
So that l will not need any nating on router H or router P for my clients to browse the net.

Am not getting any ip block from isp and router g is doing PCC load balancing.

l will like my clients to use private ip and routing to connect to the internet .

Thanks

You don't need OSPF in that network. Just configure static default routes on P and H pointing to G, and don't NAT on P and H. Then NAT on G.