Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.
There is no retainer on the pump holding the seal in place. It is simply a press fit.
As to the coupler, I have no idea. Perhaps a pump shop (most large cities have a few pump shops).
I will get into more detail a little later, busy now...