A couple of comments, almost the opposite of what you have gotten. The purpose of an advert is to draw people in as I know you are well aware. I have had quite a bit of training in advertising and I'm a big fan of "sell the sizzle, not the steak." If you list all the details everyone has suggested, you are selling the steak.
Think of going to a boat show and looking at boats. You find one you like, drawn in by the visuals then you ask for a brochure with all the specs. So in your listing start with something like "boat is is great shape, you need to see this boat in person to appreciate all the extras." That sentence would get my attention. I would then list all the basics, but at the end say that a spec sheet will be handed out on "your first visit." Also if you have had a recent survey, include that in the spec sheet.
So under electronics, don't include all the model numbers etc, but do include that in your spec sheet. So I'd say something like, "electronics recently upgraded, includes radar and blue tooth radio." Include some pics in your do it yourself brochure spec sheet.
The one thing that would seriously hold me back from purchasing your boat would be the dark interior, what I don't like about many sailboats as well - too dark inside. So if you are going to spend extra bucks, I'd just add new vinyl plank flooring (but I wouldn't use a wood colour, don't want a competing wood look) over top of what you have, I'd use something in a very light grey. This addition would brighten up the cabins, reflecting more light around inside.
Here is one sample of vinyl planking, but obviously there are many choices:
https://www.google.com/shopping/pro...X&ved=0ahUKEwiZ17Lck9rgAhVT654KHd4oDnoQrhIIIQ
Only spend money on items that will visually improve your boat (the "sizzle") and leave the rest to the new owner. Take out the bit about the price might go up if you do improvements. And advertise in the highly populated northern states, Illinois and New York.
