^not a bad idea but I've found in the past I always needed larger items blasted. Find a local powdercoater and you can prob bribe him on the cheap to blast your parts. I agree that some self etcher and rattlecan will help ALOT on the parts and prob save you a ton of money. My seat was frozen similar to yours and some pb loosened it right back up.
Merc isn't a help with anything and has been my only beef with them. I've had a pain getting some parts and part numbers for past needs which was irritating to say the least. The 555 is a nice lil system though and makes problems easy to fix along with the lp and hp fuel pumps being a big + instead of the in tank.
I love the look of the anodized red on the MCX, not sure I'd buy that engine if a clear history was provided. The dataplate on the transmission has black overspray, makes me wonder what they are so haphazardly hiding.
Not sure thats overspray or just the crappy chrome sticker peeling. I'd bet my money it being just a crappy sticker. Also you aren't going to get a lot of history on these engines unless you go new. Not sure the condition of your engine but have you considered a new block/risers?
as for the brackets I wouldn't bother powdercoating. One chip and it will start peeling. I used standard rustoleum on mine and haven't had an issue in 3 years.
Also just an fyi for your carpet. Throw some laundry detergent (non bleach) in that thing and scrub a dub dub. Run it to the 2 dollar power wash and power it out. At least then you'll know if you are going to have to replace it or not. Not sure how you like the tan in there lol. Personally I've rid my boat of all the factory light grey paneling and went to black. Would look super sharp with some non tan carpet and black that bad boy out.
Also guess I'm curious to the level you are trying to get this thing to. If you are going full out restore on this thing thats freaking great but from what I've picked up sounds like you are trying to get a budget ski boat. If thats the case I'm not sure how much I would mess with the bottom paint. There could be some hidden demons under that paint