Wish I knew mate, the guys I was using moved and I have'nt been able to track them down since
They moved somewhere to Parkwest ind estate beside the M50 Red Cow roundabout, don't know where though, don't have a contact number either, its a mega big industrial estate so you could be looking all day for them if you just drove up there hoping to come across them. I have 2 empty cylinders I would like to get refilled, luckily I have a full 5kg one which will do me for now, limited to one high tech setup for now though.