Just a thought here --
How about taking a digital photo. Then, download RASTERFRATZ - I think a demo is available. Then use that (OR some similar raster to vector program.) Rasterfratz generates g code and if you gray scale the image -- different heights.
(Not associated - just like the software)
Cheers Jim
Experience is the BEST Teacher. Is that why it usually arrives in a shower of sparks, flash of light, loud bang, a cloud of smoke, AND -- a BILL to pay? You usually get it -- just after you need it.