RE: building board
I just made a new "building-board" as an experiment and have built 4 wing panels on it, so far. It works great and cost me about £3; for the chipboard. I already had the required blind nuts and hex-head screws.
The board comprises a hollow box-section which is made from 18mm chipboard off-cuts. The DIY store cut the board into four parallel strips, using its large/accurate vertical saw.
I screwed the sections together, such that they formed a rigid box which is 5 feet long, by about 1 foot deep and 1 foot wide. Two parallel rows of 6 mm blind nuts are let into the upper surface of the building board. These accept 6 mm hex-head bolts which are used to clamp the wing structure to the board. I've made a number of wooden "clamping fingers", rather like the old-fashioned systems that were used to clamp work to the tables of milling machines.
The upper surface of the board overhangs the central stiffeners by a couple of inches. This overhang accepts G-clamps, if they should be required.
Obviously, this board won't accept pins ... but the clamping system has completely obviated the need for pins. Well, that's been my experience so far.
The system will enable me to build accurate fuselages, too. I'm quite pleased with it.