I have two thought processes on the matter... the first is what I normally think when looking over a boat that's over 20+ years old at this point, and that is that most of these things are normal wear and tear. Things break, they get chipped, they don't work or whatever else happens, happens to a 20+ year old boat. So, I think your two options would be to either fix the things yourself or have someone do it for you. Or you could leave them as is and have the sales price of the boat reflect the overall condition of the items that need to be fixed. If you're personally just wanting to sell the boat then I honestly wouldn't bother spending the time or money trying to fix the things that need to be repaired and just list it. If the boat is priced appropriately and someone comes over to look at it that is serious then these small things shouldn't be a deterrent from buying the boat. I almost prefer to not put money into a boat, or whatever else it is that I'm selling, because in all likelihood I probably won't get that money back from investing into it. The only problem with going this route is that you could not get as many people to come out and look at it, but again those people are oftentimes just tire kickers to begin with and just want to lowball you to see if you want to sell. I'm a pretty handy person with cars, boats, things around the house that need to be fixed and so forth... and as stated above, if these minor issues were presented to me on a boat I was seriously considering buying, I wouldn't turn it down just because of that, and especially if the price was right.
If you did want to do the repairs or fixes on your own, then I'd check with your local Grady White dealer to see if they have what you need as well as checking eBay or Craigslist for used items like the fish lockers, as I think those are going to cost a good chunk of change. I was selling my previous boat, which was a 2003 21' Arima, for what I thought was a very fair price and you'd have people nitpicking you over the tiniest little things. The outboard motor cowling was fading and chipping on one part of it that was maybe the size of two of my fists, and people were just losing their minds over it. I told them I had the paint as well as the decals to do it, I just hadn't gotten around to doing so with working 60 hours a week. So then they'd lowball you $5-6k, or more, based off that alone, of which one guy offered me $20k when my asking price was $27.5k. Of which I'm sure you can imagine how I responded to their offers and it seems like people in the Seattle area just expect the world to be handed to them for absolutely nothing and without them having to lift a finger. Of course the guy that offered me $20k when my asking priced was $27.5k also said he was very, very serious about the boat and then showed up in a Lexus passenger car, which I'm not sure how you'd tow a 21' boat with a vehicle like that, but alright. Luckily, the economy has been quite good for selling boats up until now and hopefully that trend continues. Good luck with your sale!