Hi Greg,
I checked the craigslist ad and she looks nice, but it's hard to tell much about a boat from the listing, and the pictures usually look a bit better than the reality.
The asking price is quite low for this kind of boat, especially with some of the new equipment bought in the last year. I'm wondering if there is something else about this boat that isn't being said--like, for example, that she has sunk at some point, which would explain the interior problems you mentioned and some of the diesel problems. While I'm only guessing, if that were the case, then I would not consider it at all, due to the potential electrical and other problems that follow a sinking.
I have owned a 1984 Ericson 30+ for the past four years, and two other boats for fifteen years before that, so I know a bit about boats (though am still learning!). It's easy to get excited about a boat, and therefore not do enough checking of all the various things that may need replacement or repair--standing rigging, lifelines, plumbing, seacocks, electrical wiring, engine and transmission, propane system, hull/blisters, prop shaft/cutless bearing/prop, fuel tank, head/head plumbing, keel bolts, keel rebedding, rudder, steering system, etc. etc.
While she may be a great buy, I'm advocating that you do a really thorough check, or have someone do this for you, so you really know her strengths and weaknesses, and what repairs you need to budget for. Our boat was in great shape when we bought her four years ago, but I have still spent at least $3,000 per year in repairs and equipment replacement. While I know I am a bit of a perfectionist in this area, I also know that boats aren't cheap if you want to keep them running safely, reliably and with relatively few problems.
Good luck!
Frank