Jed, I did post about a "thingy" that I used to scale my jointed minnow lure. Perhaps you can think along that line to make "custom" scale patterns.
Alternately, see the " seluang for DeVery" in TU galery also sometime ago which had the scale on foil pattern pre-printed with a dot matrix printer. This would be the most versatile method but a bit messy to set up but once you get the pattern done it can be accurately reproduced. Only complain I have about this method is the finest line a dot-matrix printer can produce is still too thick for my liking. But with your muskie sized lure it might be just nice or even too thin (this you can just adjust your line thickness in your graphic program - I use CorelDraw)
Have fun tinkering.
(Sorry I'm no good at finding old post, but a copy of the seluang lure I have it here: http://www.pbase.com/sebarau/seluang scroll to the end, last pic, click on pic for larger view)