Several possibilities, including the Skipper
It could also be a Groco EB (discontinued, no longer on their website, but parts still available) or Model K (still in production. Drawing on the Groco website here: http://www.groco.net/images/toilets/Sec1-Sanitation-SM/Series-K.htmThere's even an outside chance it could be "Baby Blake" (made in the UK).Unless your boat is Nonsuch, it's unlikely that it was original to the boat...'cuz all those makes/models are VERY high end manual toilets, with prices of $700-$1,000...made to last 100 years or more with reasonable maintenance. So even if it needs parts that cost more than the toilets you don't consider "unsightly," it's worth the expense to maintain it. Tossing it out for a Jabsco just 'cuz the rebuild kit costs as much as a Jabsco would be tantamount to tossing out a Rolls Royce for a Yugo just 'cuz a tune-up for the Rolls costs as much as the Yugo.In fact, if you pull it out and strip all the paint off it, you may not think it's all that unsightly after all (especially now that you know what it costs!)...'cuz what's under all that paint is solid bronze.Take a good photo or two (all bowls look alike, so don't just stand over it and shoot down...get it from the side and the front so I can see what the pump and the rest of it look like)...email it to me (I'm in all the directories here)...and I'll be glad to identify it for you, then give you the contact names and phone #s for a manual and tech support for it.