I am not overly fond of the method whereby the plans are laid under a transparent, glue resistant material and the jig built on top of that.

Tony Bingelis (sp?) transfers measurements from the plans to the jig board.  I have problems with that approach, too.  My method is to tape carbon paper (yes, you can still buy carbon paper) to the jig board, tape the plans over the carbon paper and trace the information onto the fig board. 

The long metal rule ensures that the spar centers are exactly 31" apart.  It also aids in tracing the information.  The drawing lines are not straight?  A bit disturbing.