If you want to use Camping Gaz but have a Calor Butane set up use an adaptor easily available from that large on-line retailer – Camping Gaz Adapter For Motorhome & Caravan Regulators Fits 907,904 & 901 : Amazon.co.uk: Automotive
Apparently despite reintroducing the 3.9 propane and 4.5 butane cylinders, Calor still have huge supply issues so don’t hold your breath….
Apologies, the linky doesn’t work….