A couple of my brothers and one of my sisters are getting very interested in prepping and one of them is an engineer who is quite good at building things and improvising. I can see him building something like this.
I have been focused more on developing skills (particularly medical-related, because my interest has always been health care) that will be useful after SHTF. I do have a "short term" supply of freeze dried foods and other items to help through a transition phase after a SHTF event.
I don't think I would say I am "happy" with what I have because I'm always learning knew things, adding items, changing things up and trying to improve my supplies, as well as my knowledge.