I just took my BOC bottles back and switched to rent free ALBEE. Its the french AirLiquide but hey-ho...
http://www.albeegascylinders.com/Its about £20 more per fill but the bottles certainly look a lot bigger. I use so little I didn't keep going with the research to see how many KGs empty vs full or what pressure each is loaded to or anything like. I just wanted to be able to go in the garage without the bottles shouting at me "money each year for what eh?"
Deposit £100/bottle against £130/year for the BOC pair so it pays back in under two years. HobbyWeld is the other company out there but more expensive for acetylene.
http://www.hobbyweld.co.uk/I felt a lot better being told it was only April last year acetylene became available rent free, not sure if that is true or not but made me feel a lot better about my wodge of BOC bills.
Other options are Oxy Propane - BOC stock a Harris kit. Also discussed on the Austin 7 forum (the trigger to my change) is a Rothenberger kit. I saw one in the BOC shop and the cylinders are tiny, household aerosol sizes.
http://www.tradecounterdirect.com/product/rothenberger-roxy-brazing-kit-120l_type.htmlDavid