I actually learned photoetching on that 70-tonner project for the steps, handrails, etc. and gave it completely up as the messiest, most expensive, hazardous, and least efficient use of my time I've discovered yet. Crossed it off my bucket list of skills, like putting on a house roof, I'll never do that again. Sold all my equipment.
My photoetch service is excellent, but running around $550 a sheet, that's an expensive cab. I have another project underway that economically works out, but not this one.
And a photoetch cab would still have the problems of roof edges...somewhere, rather than the smooth all-around curve of a GE cab that should be there.
I'm molding something now just about every evening. I've done Shapeways successfully, but it's not a workable business plan and their marketplace search is just totally and completely worthless. My middle son has really mastered 3D printing, but by the time he gets one 'perfect' I could have scratchbuilt a master and made it in resin about six times over.
The windows on that 70-tonner cab are .010 x .020 strip master. And unlike FUD, this stuff doesn't shatter like glass if you sneeze on it.