Hi 92inboard2510, Welcome to ClassicParker and congrats on your new-to-you Parker 2510!... You may have noticed a lack of responses to your post, which for the most part reflects what you said; 'seems to be pretty rare!". You are correct; there are not-many Parkers with I/O's but a few members here have posted some pictures and comments over the years..... Back in 1978-1983 we had a 22' boat with an I/O (it was a Mercury 470, 4 cycle, four-cylinder, Chevy block, FWC engine, with stern-drive). The things we liked about the I/O (similar to yours) were the Fresh Water Cooling system/heat-exchanger, the fuel-economy and the ease of maintaining the engine. We were not crazy about the space the 'box' took in the cockpit, but learned to live with it (used it for a dining table. A sunning bed. A bait cutting table with the cushion removed). It seems that stern drives were more prevalent back then..... I hope you and your husband enjoy the new boat!