Hepaestus,
Out of curiosity (and not to pin you down), what is your goal for all this really nice work you are doing?
1) Create a set of unambiguous, correct, legible digital drawings for the original J-2?
2) Create a set of digital drawing of a new plane derived from the J-2 (a bit wider, higher gross weight, a little more fuel, taildragger)?
3) Same as #2, but using other construction materials instead of wood in some places.
Any/all of these are great and worthwhile objectives. At my current (low) state of knowledge, if I wanted to do #2 or #3, I'd probably start with a good look at the J-2 structure to understand the loads and how they are reacted in that original before going my own way. I think that is what you are doing now with the number crunching.
On the wing loads and attachment pins with a wider fuselage, do they change? In my uninformed view the answer likely depends on where we consider the wing shear load ("upward force") as terminating. If we are working with the assumption that the shear ends at the first pin it encounters (and the distance from that pin to the wingtip is unchanged by the fuselage widening), then no change to the spar calcs is required, and any lengthening of the distance to the second pin will only reduce the (downward) force on that pin. OTOH, if we are working on the assumption that the terminus of the wing shear is at some point between the two pins, then the spar length does change if we increase the distance between the pins. My caveman view is that there will be an "up' force on the first pin and a 'down" force on the second pin, so the actual end of the wing shear forces (zero up or down force) is somewhere between them. If that is right, then increasing the distance between the pins changes the effective spar loaded length and the calculated loads. But, it would be WAY better to get the opinion of someone who knows what he/she is talking about
The renderings are great, thanks.
Mark