Good on you for all the work you've accomplished so far
Epoxy can be kind of fun once you thicken it and make it do things, can't it
I can't say for sure whether you can move your hinges or not, but what I have noticed is that some of the Boler
13s shifted hinge locations between the early and late 70s. They went from being highest and lowest to the top being not so high and the bottom one being not so low (at least on some trailers).
I think I may know at least on of the reasons for this: On the earlier Bolers, ones with the horizontal, Hehr brand crank out window (square edges with an oval looking inside part), I had noticed that many of the window frames looked a bit "chewed up" on the lower, front corner. Huh
Well, I found out why: Just try opening the door with that window partially opened. Yep, it catches on the top door hinge. So I'm thinking maybe they then decided to move it down a little. Then, I have the feeling that the upper and lower hinges have to kind of "match" as far as where they are in "in/out" orientation (in other words, a theoretical vertical pin should go through both hinges in the same place), so they had to raise the lower one the same amount they lowered the upper one, is what I'm thinking.
So, there is precedent for the hinges in a few different locations; but there may be something to having them both "match" in their location (vis-a-vis the theoretical vertical pin). I don't know that for sure; just guessing on that one.
Here is an example of the older hinge spacing. You can see how the window and hinge could interfere with each other:
And here is an example of the (sometimes) later hinge spacing. Now there can't be a collision with the open window. You can also see how the lower hinge has moved up, possibly because of the "pin" alignment issue (?)
Again, congrats on what you've done so far!
You know, now that you are good at working with epoxy, you might consider not making all the new rivet holes (assuming those are some of the ones you filled in), but instead tabbing the furniture in on the inside, with fiberglass tape and epoxy resin. Stronger and cannot leak, plus no rivets to see or to need to maintain.