MeFlood from your description I beleve what you have is a contemperary or modern type from many manufacturers with many of them being of eastern europeon origin.

The givaway is the presence of a separate charging line for the flight tank. This is inaddition to the tank to cylinder line.

After WW11 in this country there was a flood of surplus small steel CO-2 bottles avalible very cheaply. These I beleve were primarily used for self inflating life vest. Although the bottles were quite heavy they were a natural for a simple CO-2 engine.

In the photo is an example of an OK Cub CO-2 engine that was introduced sometime after WW11 to use the heavy surplus bottles, these engines were produced in the thousands. It is these original small heavy steel bottles that are hard to find now.

Viurtually all the contemperary engines use a separate flight tank and a charger or charger tank. The flight tanks are lightweight spun aluminium and always have a second charger line that the charger plugs into. The charger tanks are common and CO-2 is very cheap.

The line from the flight tank always exits the top of the tank and the line to the cylinder always has a loop or multiple loops in it as this is provided the heat that aids the liquid in its expansion to a gas so the power can be produced.

John

Here is a vintage Cub designed to use the war surplus bottles: Sorry I can,t find the picture of my little OK but did find this pic of a magnificient Gasparin that illustrateds the light tank and extra charging line, definately not mine but sure wish it was