I took a few pictures of my DIY stand door panel as it seemed to work very much like I wanted. The stand is getting somewhat old and beat up but I am prepping for a move and likely will be selling the stand. So if you notice some loose equipment or "experience" on the door, that's due to the situation, not the way it was originally.
Some info on how/why I built it this way. I wanted a "built-in" look but without actually cutting studs or permanent work on the walls. I wanted it to somewhat match existing trim and wall colors. I wanted simple and somewhat quick but also good enough for public view next to a table where we have lots of meetings and visitors. Primary point was how easy to build and work as well as being able to move it later.
The support stand is basic 2X4 for cheap, sturdy, and durable, with a relatively cheap, simple skin with butted corners to allow for quick easy cuts and trim to match existing over the ragged panels ends. The whole builtin look had to be designed with taking it apart in mind. So it came down to building the stand, build the box frame around the tank and then a canopy on top. When moving comes, and it always does, I can take the canopy off, pull the front frame, move the tank off the stand and then move the stand. All in pieces which are easy to manage.
I like simple easy to build tools and painted matched what I wanted for this item but the idea is adaptable to the finish that we each might like. Reasonably cheap and easy to build with only moderate tools and skills needed.
For the panel, I wanted to have one large panel which comes off to set back out of the way as I find twenty pound CO2 tanks are pretty awkward. I also do not want much lip at the bottom to work over.
So pictures are:
1. Overall view.
2. Panel corner showing the panel is a piece of the basic skin cut out and trimmed with standard molding.
3. Bottom track showing the xtra board behind the bottom trim so that a slot is formed for the panel to drop down into.
4. Top area where I have the magnets for holding the door from tilting forward to come out. The added board inside at the top is to act as a door stop to keep extra pressure from knocking the panel trim loose. I also found this to be a very handy space where I could mount the needle valve inline and where I could both see the reg and easily reach the adjustment. Fabco NV-55 needle valve.