: Make sure it's an architectural repro machine, rather than a simple
: photocopier. You don't want the copier's optics to introduce any
: inaccuracies in the plotted stations.

if there are inaccuracies, likely they are small and consistent - so one way around is to blow up/down only half a form and then use your window, lighttable(hey or your computer screen on white), thinpaper, trace or this flipped cut form to get the other half exactly cut or drawn.
the resultant sections will be close enough.

(or if you have/rent a projector, just throw on far the wall(hard so no movement) and trace out those.(hehe how about a 100ft long yak??)

mind you if the inaccuracies are high, even if the sections ARE all screwed up, you'll get a symmetric yak. (hehe)