I took a crack at making this myself attempting to do it with materials that wouldn't require painting. I initially printed it out with the parts listed here plus the textured grips and the modified under barrel components. Then found a fused version from Guido Maurizio, but it was incorrectly fused. Luckily someone had posted a link to Andrew's properly fused models, so I used Guido's text on the upper barrel as a template and updated the model to emboss that on the side. I also printed the right chamber cover dial Guido had (after scaling it down a bit) and modelled a notch in the right chamber cover for that. The last part I printed were the grips, which I printed with 100% infill since they use translucent orange, so that also gives the gun some weight which is nice. (Took about 9 hours each to print, though, since I also slowed the speed down to aid in translucency). I will also admit I had to sand a few parts down, so even though I didn't paint this, I did spray down the parts I sanded with some clear enamel I have. I think it worked out well, though, since it gives the black parts a matted look.
I still need to add the LED lights to the under barrel compartment, but aside from that it worked out well. The only problem is the trigger springs did not work out well at all, so the triggers have no return action to them. Minor detail. Part of the issue may be that I printed those thin bits in PETG since I was afraid PLA would snap under the pressure.
I have to compliment Andrew on creating this. I appreciate how clever some of the solutions were to getting the right on it.