One thing I've found about my 1977 Catalina 30 Hull 662 is that I have access to everything. I can access my batteries, engine, fuel tank, water tank, waist tank, etc. Other boats in the marina have had to have their engine removed to replace a leaking fuel tank. Yet others never check their battery fluid level because "it's a pain".
My old boat is new again! I've replaced EVERYTHING except the mast, hull and engine. This winter I will be replacing the keel stub, my last "have to do" job on my 30+ year old boat.
Because of the after market parts, my boat no longer looks like a MKI, I have done the traveler upgrade, I've upgraded my windows with Cruising Concepts Black Acrylic window replacement, I've upgraded my forward port, again with a Cruising Concepts Acrylic port. My father (the engineer) made me a double anchor roller plate that fits under the forward pulpit and cleats. It has all the room I need and is easy to single hand - something I love to do.
When I started looking for a new boat, I decided I'd rather upgrade the boat I own - after all I know all about it and have TONS of resources to go to if/when there are problems.