If you need gas fittings, try Jerry Watson of Clevedon Steam.
He used to work for Cheddar Steam until it folded. He has taken on most of the ‘useful items’ range. I suspect that will include the pipework and the gas jets as well as fittings for filling tanks and connecting to disposable cyinders.
If there is something he cant supply directly, he will almost certainly point you in the right direction….
His email is [email protected] or phone him on 01275 871381
I use disposable gas cans from my local hadware shop, these are propane/butane mix. I have fittings for direct connection and fillers for small tanks place inside models. All my boats use a No.8 gas jet and have ceramic burners for the boilers.
Hope this helps you,
Phil