When you get to within about a foot of the bow and stern, the deck needs to be pretty much flat, or you'll never get it sucked down to the sides. the angle varies from flat at the bow and stern, to what matches the bulkheads.
Normally you can recoat over partially cured epoxy without a problem (most say within 24 hours, but ambient air temp varies that time). The company that made the epoxy should have a web site with details.
I'd change out the 90 degree elbows for 45's, or eliminate them entirely. Makes pulling wire a lot easier. I'd also put in a pull string now for pulling the wires later. Needless to say, don't ask me how I know ;D ;D ;D
Be careful with the fitting of the decks at the bow and stern. the deck needs to transition from arched to basically flat as you approach both ends. Gappitus will happen if you try to maintain the arch all of the way to the ends. Other than that and the washer trick already detailed, it's a pretty straightforward build and a nice performer on the water.
Good luck and enjoy
Marty
I recently finished a birder II modified to hold only one person(similar to CLC's Mill Creek). I decided to try it without any appendages and that is how it will stay. The boat tracks just fine as is. It doesen't seem to be bothered much by side winds, but then there isn't a lot of boat above the waterline to catch a breeze.
Marty