I had some requests for the final configs so I have fixed those. You can download them here. Also I had some issues getting the traffic through but thanks to my helpful readers like zumzum I now have it figured out.
Lets start on R4 since this is the source of the traffic.
R4 wants to send traffic to 188.8.131.52 with a source of 184.108.40.206. We know that route via RIP and the next-hop is 220.127.116.11. That network is directly connected (secondary). We need to find out the MAC address of 18.104.22.168 for our ARP entry. R3 has proxy arp enabled, which is the default. However it will not respond to R4 ARP request since it does not have the subnet 22.214.171.124/24 connected. R4 must therefore have a static ARP entry. I did an error here earlier by typing in R1 MAC but this should be the MAC of R3 Fa0/0 since that is the link connecting us. We create the static ARP with arp 126.96.36.199 xxxx.xxxx.xxxx arpa. R4 now has all the info needed.
Packet travels to R3. R3 does not have a route for 188.8.131.52. We create a static route, ip route 184.108.40.206 255.255.255.0 220.127.116.11. We also need a static route back to R4 for the 18.104.22.168 IP. Ip route 22.214.171.124 255.255.255.0 126.96.36.199.
Packet now travels to R2. R2 also needs to know about 188.8.131.52 so we add a route there as well. Ip route 184.108.40.206 255.255.255.0 220.127.116.11. R2 also needs to find its way back to R4 so we add a static route, ip route 18.104.22.168 255.255.255.255 22.214.171.124.
Packet goes to R1 which will respond. It will send the packet out Fa0/0. R1 needs to know the MAC address for 126.96.36.199. R2 has proxy ARP enabled so it will reply with its own MAC address to R1. R1 will insert this into ARP cache and adjacency table and then we are good to go.
So except learning a multicast feature we also got to practice how to make connectivitiy in an unusual way and think through the whole process of packet flow.