Nope can't help you with that, i can tell you that "tp 206 bar" is test pressure," 06/92" will be the month and year it was made, "BS 5045 pt.6 1987" will be the standard it was made to, "co2" self explanatory that one, "ew 580g fw 930g" is your empty weight and full weight, and numbers such as "208954" will be that bottles own unique serial number, no idea what "luxfer 7920159 212 139 l" refers to other than Luxfer being a manufacturer. So no help there really, but i would say they really old bottles.