Looks a bit suspicious at the moment.
Contact and product pages are the only things that have been changed from the standard template and as you say, no address, which is a big no no.
I have also been looking at this one - It appears to be connected with http://*removed for legal reasons*.co.uk also of St Helens as the "Welding gasses Online" link is redirected to www.weldinggases.co.uk
I use them guys there good, i get my beer gas from them c02 and c02/nitrogen. This is where i will be getting my argon/co2 from as well when i start welding.
There address is,
340 haydock lane
Haydock Ind Est
St Helens
Wa11 9uy
Iv always phoned up ordered my gas and gone and picked it up from them.