hi, if you want i can send you norman's email. he sells the grey 2kg cylinders with screw tops for £40 or 2 for £70 inc postage i've got an empty 2kg co2 fire extinguisher lying around aswell but it doesn't a screw valve and i'm pretty sure it's either gone past its test date or the test date is in the next 6 months, you can have it for free if you want. i found it useful when designing/making measurements etc before i got my cylinders off norman.

can't wait to see cabraken 3