Good advice on concentrating on the important features rather than trying to make an exact copy.

For copying shapes in CamBam, in the past, I have scanned (or photographed with a long lens) parts and then traced them in inkscape and exported as a DXF - CamBam will read this directly and you can then create the MOPs to make the cuts. If you have a ruler or known size object in the shot it helps getting the scale right (you can easily adjust the scale in CamBam).