Bill, that is a scary long tongue! Obviously it works for you but it looks like it needs some bracing to keep it from bending if you ever got it in a bind backing up.

I just got mine stripped of the wood frame for the boat it was hauling. My buddy bought the boat and I got the trailer. My trailer is probably 40 years old but it is similar to yours. I need to extend the tongue and probably going to have to build a new box/frame. It is a little rougher that I thought. But the main thing I wanted was an axle to work with. And this one is sprung perfectly.

I like a lot of the ideas you used! Will probably steal some.