You may want to run some conduit for your wiring. Will help keep wires up out of the way and keep dogs, or what ever from chewing on your wiring. Seems most trailer makers fall short of the mark when it comes to wiring. Also, I don't think it was mentioned, check all of your spring bushings, if they need replaced, I'd for sure try and replace them with Poly type bushings. That way you can grease them with no worry of the greats eating the bushings. Also, as cheap as they are, and, it sounds as if you are trying to do all you can, I'd replace the brake backing plates. They come with all new brakes and cylinders. Have drums turned if needed, and or, the magnetic part on the inside of the drum face resurfaced, If the aren't too bad. If they are in bad shape, I know of one place that seems to have it all in one place kinda store, is Redneck Trailer supply in Lincolnton. Also you had mentioned getting it sand blasted. If you go that route, Make sure they seal off the hubs/drums as sand will get anywhere you wouldn't think it could. If you go the brush road, get you a descaler from Harbor Freight. If you have access to air. As was also mentioned, before laying down new decking, make sure to put in place anything you want for your trailer such as a winch, storage boxes, spare tire holder and so on. If you are lucky enough to source some white Oak boards, that would be great, but, if you go the treated board route, wait till summer before you treat it, so you can get it really dried out. I don't care where you buy it, it won't be dried enough. I saw where ATF was mentioned to treat the boards, I have never used it, but kinda the same route, I have used used motor oil thinned out with some diesel fuel or Kerosene. just paint it on and let it soak in, and repeat as many times as it will soak in, then wipe off the excess. Also, add as many tie down points as you think you'll need. And once you get it all nice a pretty from painted, some some reflective tape on the sides. Some places seem to think they are made of gold, but, the Harbor Freight reflectors seem to work just fine and are gonna break the bank.