Just a couple more comments about jigging the wing or wing 1/2s. I use straight spruce stock of various dimensions to support the LE and TE of the wing. I use a 36" straight edge and alignment marks to ensure accuracy - a laser pointer/level would also help! I use 1lb lead weights to hold the wing in place (lots of them) at the main spar location, LE and TE.
I sheet the TE first: remove the weights, trim sheeting to fit and adhere to wing with slow curing/thick CA, after sheeting is added I replace the weights and allow the CA to set. The LE is a little trickier as the airfoil contour requires some bending of the sheeting (I try to use the softest sheeting available). MK kits use the LE and TE to help align the sheeting as it butts against these pieces (so they need to glued on before sheeting). Again using thick CA, I apply the CA to the LE of the sheeting then the ribs and finally the spar (if the sheeting extends back that far). I butt the sheeting against the LE and use small pins to hold in place (usually the LE extends slightly above the sheeting; so I pin above the sheeting into the LE - then the pins don't get glued to the wing!!) - a pin at each rib and 1/2 way between each rib. Then I bend the sheeting down to meet to ribs/spar holding it in place with the 1lb weights. I start iin the middlle and work out 1 rib bay in each direction at a time. Check the fit of the sheeting at the LE and add pins as necessay (I use the smaller 'T' pins 1" long or shorter). The remaining sheeting/cap strips is now very easy to add.
This is just my approach that I've refined after building a few wings. I'm sure there are other good or better solutions. As an aside, I've been building since the late '60s and the arrival of CA glues not only sped up the building process, but eliminated the need to use 'warp-inducing' white glue. As an alternative to CA, the new Carpenter's glues also seem to work very well, but the cure time is much slower (but faster than the 'good old days' )
-Happy building!!
Will