Stuff you can look for
There are a few things to look for. O'Day had a couple of designs for the centerboards of the 23, which changed year by year. I have seen two centerboard arrangements: on one design, the swivel bolt for the centerboard goes all the way through the keel and is accessable from outside. If you can see this bolt, it would be a very good idea to check it for corrosion, etc. Also, while the boat is out of the water, check the condition of the fitting that attaches the pennent line to the centerboard. If you replace it, make sure that it will not catch in the trunk when you retract the board. I assume that you will want to try and find out why your board is sticking. Its probably either marine growth in the trunk, a too-big pennent line fitting, or a centerboard that has absorbed water over the years and is too big to fit anymore. The first two are easy to fix; the latter is most likely. I think Rudy at D&R Marine (508) 644-3001 has the mold for the 23 centerboard and can make you a new one. Or you can do what I have done: just not retract the board all the way. The last time my boat was hauled, I played with the line until I found out how high I could raise the board without sticking, and I marked the pennent line in the cockpit with nailpolish so that I wouldn't retract it too far. At least one other O'Day 23 owner in my marina does the same. As far as painting the bottom goes, there is no reason you can't do it yourself. However, I don't since I make it a policy not to muck about with highly toxic substances. I recommend using the newer paints that will retain their ability to control growth for more than one season. Two coats should be fine (remember to get the centerboard and inside the trunk). I would also get two different colors, so that you will know when one coat wears off (you will be able to see the other color underneath). This type of paint is about twice as expensive, but it all evens out; it lasts longer. I did not have to paint the bottom of my boat this year at all. As to the stern pulpit, I have never seen a 23 without one. Ask Rudy about a replacement. My guess is that you would need to have one custom made, but maybe he has some different insight. For your rudder, when Sailing magazine reviewed the 23 last year in their Used Boat reviews, they noted that the gudgeons and pintles were noticeably undersized. Might want to take this opportunity to upgrade. Have fun.
