I would think that fire/UL/certification, etc. would be covered by the wall-wart (or line-lump?) external power supply. Your board appears to want low-voltage power input through the "inverted-phone" power connector.
As others have mentioned, if you need to have it rack-mounted, you really need an aluminum or steel rack-mount chassis. Several manufacturers make stock items that are available off the shelf. For example: BUD CH-14401 That style available in several different depth dimensions to suit your board.
Even available from Amazon!
(at an inflated price) depends on how carefully you shop on Amazon.
I found them from another vendor for the same price as Mouser/Digi-Key/Allied (within a few cents)
I didn't see where you mentioned whether this was a one-off, or some production-run of several?
If this is going to be deployed elsewhere by others, and especially if it has any kind of critical dependents, I would want to at least make two of them, one for production and one as a "hot standby".