Work got in the way, so it took a little longer to get back to you
What you're doing with Samba is communicating between the Linux and Win-OS boxes in the protocol used by the Win-OS. It allows you to 'discover' the services the Win-print server offers (i.e. the printer) via the desktop. No need for ssh sessions!
Anyway, back to Cups: for a remote printer to function like a local one, you need to install the printer in Cups, as it were a local printer. But in the location field you enter the IP address (and printer spool) of the Win-OS box that acts as the printer server. I'm not sure your Epson is (properly) supported in Cups, IIRC Epson is one of the worst regarding Linux support. HP and Brother have much better Linux support (I have a Brother MFC and it's not the first one!
) so perhaps you can persuade the remote users to switch over to a better Linux supported brand.