It is indeed a Raritan PHII. It's not likely to be original to your boat...The OEM toilet on Hunters are Jabsco. Nor does it appear to be an "older version"...it' pre-dates the PHII SuperFlush version but not by much...the shroud cover is just missing from the base. However it does appear that a previous owner made the mistake of adding a motor to it, then either saw the error of their ways (adding a motor to a PHII turns the best manual toilet on the market into the poorest excuse for an electric toilet 'cuz it only replaces the pump HANDLE) and removed it or the next owner did.
What advantages does the upgraded pump and base provide?
Raritan redesigned the base a few years ago to change the mounting bolt pattern to make it a "plug and play" replacement for the Jabsco and other manual toilets and renamed it the PH SuperFlush
Raritan PH SuperFlush Promo Sheet It still uses the same PHII pump that has been the top rated manual toilet since Raritan introduced it in 1983...This is the owners manual for it.
Raritan SuperFlush Owners Manual It only needs to be kept well lubricated, a new joker valve annually, and a rebuilt kit (PHIIRKC--about $60) installed about every 5-6 years to provide at least 20 years of reliable trouble-free service with minimal repairs needed.
As for what makes the PHII a better toilet... Because the diameter of the piston of the PHII is 2 1/2 inches, whereas the diameter of the piston of most other manual toilets is 1 3/4", the PHII will pump twice as much per stroke than it's competitors will. The lever pump handle reduces the amount of effort required, so you only have to pump half as many times to flush it.
About that leak at the base of the hand pump...check the pump housing for a hairline crack. Easiest way to do that: put some red food coloring in a quart of water and flush it. No red stain on the pump housing, no crack. If you don't find one, instead of opening the pump to replace one gasket, then again to replace the joker valve, and again to replace the flapper valve... I'd spend the $60 for the rebuild kit and be done with with all of 'em except for a new joker valve annually for another 5-6 years. It's prob'ly due for a rebuild kit anyway. If you do find a crack, Defender has a replacement pump housing for $69. You'd still need the rebuild kit, but the total is half the price of a new pump assembly.
--Peggie