RTR3
Changes made:
ip route 10.10.10.254 255.255.255.255 Serial0/0/0
ip nat inside source static 209.165.100.1 10.10.10.254 

router ospf 1
no network 209.165.100.0 0.0.0.255 area 0
network 209.165.100.66 0.0.0.0 area 0
redistribute static subnets 

int ser0/0/0
no ip nat inside
ip nat outside

int fa0/0
no ip nat outside
ip nat inside