Welcome to the site. I have built my own gun cabnit but no plans. Just played it by ear. I like cabnits better than safes, seems this country is in one hell of an uproar over everything anymore. I took a different attitude and taught my kids about guns. Would send you a photo but haven't re-done it yet since my house burned.
Just keep in mind, your building a box to keep your guns in. Take it from there.
Let me start off by saying I am not a farmer.
I am a deer hunter and I do own a tractor and have all of the equipment - but that does not make you a farmer any more than standing in the garage makes you a car - well, you get the picture!
Having said that - and with most of my ineptitude fairly well hidden - I do think that buckwheat is one of the most under rated cover crops out there.
I say cover crop because I see mixed results as it relates to the deer eating the plants.