back-to-back lounge seats

Hi guys, I'm new to this forum and the boating world. I recently inherited my great uncles boat, its a 1992 SeaRay Overnighter Limited. It has been sitting for 5 years now and needs some work on the upholstery, the motor has been winterized since he last took it out, its also still in the break...

We need to replace the seats in our 19' Cuddy 1999. Several vendors online offer product described as fitting "most" boats in certain size ranges. I want to make sure that the product I purchase will actually fit in my cockpit. Of course the dimensions are specified in the product literature...