I designed the linked 3D print on Thingiverse. Whilst I based my design on the Carclo reference drawings, it’s far from perfect but is functional; GITD brightness/duration/colour is entirely dependent on the filament selected, though I’ve yet to see a filament that can hold a candle to the handmade CRX ones, I imagine because the amount of GITD material is limited in the filament, in order that it is still able to be printed; GITD filament colour options also seem to be very limited (green or blue is about it), plus ABS GITD is even rarer; PLA GITD has more options/availability, but starts to soften at around 60c which I believe would be less than optimal (ABS doesn’t start to soften until over 100c I believe).
I printed in EICE GITD ABS green and whilst initially fairly bright, dims rapidly, though with night adjusted vision is visible well into the early hours. Addition of trit vials is the best of both worlds and to be honest, I may go back to a black gasket (as I loved the look) with trits.
If I can get away with International Economy, I’d be happy to send a few over to you, if you wish?