Regarding Terry Hubble’s letter that he cannot locate a Rego-Push device for fitting gas regulators to cylinders, I have one and I got it from P. Alcaraz e Hijos, SL.
On the main road leading into Los Montesinos, Tel 96721330/ 966721600. Cost 21.09 euros. Spanish name is Accesorio Quita Reguladores de Ref 0104218. I found it difficult to use but it does work.