Decided I wanted a Stimpack from Fallout 4, so I fired up Blender and modeled one as close to the visual appearance of the game model as I could (albeit a bit more high-poly). Printed, smoothed, and painted it, et voilà.

Nerdy technical details:
Printed on an Ultimaker 2 in PLA (0.4mm nozzle, 0.12mm layer height, except for the gauge needle which used an 0.25mm nozzle with 0.04mm layers).
Tried using XTC-3D to smooth it, but it beaded up instead of self-leveling (the only thing I can think is that maybe I'd finally manage to calibrate my printer well enough to print too smoothly for the resin to have anything to really grab onto), so I went with old-fashioned sanding.
After priming, I painted it (mostly airburshed, except the black bits in the center). I decided to try salt masking for the weathering, which turned out even better than I'd hoped.
Apart from the 3D printed parts, I used a test tube to contain the "medicine" (a red ink), copper wires (which I tried to age, but the wire seems to have an anti-tarnish coating on it), the label, and a quilting pin for the "needle".
I put the model up on Thingiverse, for anyone who wants to print a copy.



Nerdy technical details:
Printed on an Ultimaker 2 in PLA (0.4mm nozzle, 0.12mm layer height, except for the gauge needle which used an 0.25mm nozzle with 0.04mm layers).
Tried using XTC-3D to smooth it, but it beaded up instead of self-leveling (the only thing I can think is that maybe I'd finally manage to calibrate my printer well enough to print too smoothly for the resin to have anything to really grab onto), so I went with old-fashioned sanding.
After priming, I painted it (mostly airburshed, except the black bits in the center). I decided to try salt masking for the weathering, which turned out even better than I'd hoped.
Apart from the 3D printed parts, I used a test tube to contain the "medicine" (a red ink), copper wires (which I tried to age, but the wire seems to have an anti-tarnish coating on it), the label, and a quilting pin for the "needle".
I put the model up on Thingiverse, for anyone who wants to print a copy.