Wow, your really tearing into the ole gal!
I know we all go different routes in our restorations and if you get the chance read some of the other Chief threads then you'll see how much different we all are in our efforts. On the motor, that's great she fired right up and runs after sitting for so long, normally that doesn't happen. I would take that as a great omen! Definitely put a water pump kit in that lower unit, the water stream doesn't tell the whole story, the rubber becomes brittle, worn and is normally replaced every other year. You don't want those vanes to break off and get inside the power head.
I agree with JB on the foam, not the best choice to use that type of foam for flotation. I also noticed that you ran the decking long ways, it should be ran across the boat for strength and that's how the floor supports are designed to have it lay. I know it uses more to do it that way but it's the correct way to install it. If those floor supports are at all loose, they need to be re-riveted down too.
Keep up the forward progress :thumb: