Quick 'N Dirty detail drawing to give you the idea of the size/scale Russ
As far as the # of blocks to build the small bug, I'd say in the 150-200 range... but I got bored after casting around 20 of these things and never made it to enough to build a bug
I have the 3d cad file, not sure what format it needs to be for the rapid prototype places. I gave it to someone last year but I don't think he ever did anything with it.
I really like the idea of building a metal version but the price will be prohibitive.