Seltzer Bottle Charge holder

This is a CO2 charge holder for older seltzer bottles. The seltzer bottle works in a similar manner as the modern "Sodastreams" but uses a smaler single charge cartridge, held in place with the charge holder for as long as the bottle is pressurised(Valves was fist used in the 20s).
As the original cap does not fit modern cartridges I had to make this charge holder to be able to carbonate the water. Specificly it fits seltzerbottles of the Aerators LTD (Pre 1920s). The thread on these bottles does not fit modern adaptars eighter, thus the need for this printed part.
Disclaimer: Pressure, danger, use caution, you are yourself responsible and so forth