the welded nut is the nut that comes with the air cylinder
Most folks that post here are sharing ideas for the benefit of all - not patented, even if it is a great idea and something that might sell. So - I don't think the original poster is looking to sell his invention, just share it - you are free to make your own.
You will have to do your homework - look on Google for the air cylinder, find a local welding shop that can look at the photo and weld up something. You probably have local folks that can powder-coat it for you too. You can find feet, endcaps and pneumatic hose at McMaster Carr, for example. You'll have to take some of your own bottles and figure the height, width, depth. I would start with the air cylinder and build around it.
the bell that crimps the cap might be purchased, or you might sacrifice your hand capper -