2001 RAV4 Manual Transmission - Extension housing oil seal

I need some help with the correct part number for the extension housing oil seal. I need to replace the extension housing oil seal on the transfer case but I'm not sure of the correct part numbers. I've been getting the run around from parts places.

Also, what is the correct gear oil for the transfer case? I believe it is 80W 90 GL5 but I want to be sure.

Any help would be much appreciated.

Thanks in advance!
Frank