Thanks Dom,
Seems to answer most of what i was asking - the email that you quoted from andy clarke was a copy of the mail i sent to jetsam industries ( havent heard back yet) and to andy which he said he'd posted on a rebreather forum - small world.
Anyway cheers for the info, my email address is
duncan@vincent1691.fsnet.co.uk if you could sent it onto the kiss list with andy's that would be great