Mine has a Botto Gas decal on the back. It is an LPG lamp. Not much info on Botto gas to be found from that era.
Welcome aboard! The links below show relevant information, but the library is only open to subscribers. https://classicpressurelamps.com/threads/tilley-lp-gas-appliances.17291/ https://classicpressurelamps.com/threads/1960s-bt25-and-bt25g.4779/
Thanks for getting back to me What age do you think is? would it have been used on the railway, or ships/military. Any information would be great to hear. Once again many thanks Mark
Without actual documentation such as adverts it's difficult to be precise about dates and it could have been used anywhere, including on canal barges. This link shows the results of a google search for Bottogas. bottogas - Google Search