Don't know about the ar-7 mods, but did see a show with Les Stroud, aka survivorman. He made a standard .22 rifle much more "survival" focused by drilling holes under the butt plate to hold extra ammo and other needs. Pretty interesting idea.
Closest thing, I believe was the Butler Creek Packer Take down stock.
Discontinued however...
They still pop up from time to time on eBay and Gunbroker-
Otherwise another great option would be the Marlin Papoose!
Here is the BC-
Closest thing I can think of for a 10/22 that's currently out there might be putting a Butler Creek folder on a Compact model 10/22. It wouldn't make for quite as small a package as an AR-7 or Papoose, but it'd do IMO. You could get a 16" barrel for your existing 10/22 and do the same.
Personally, I picked up a nice Norinco Browning ATD copy very cheaply, fixed a broken extractor (the Browning part dropped right in), had a Lyman 66 receiver sight installed and replaced the stock open rear with a Marbles folding leaf. It makes for a pretty small package, taken down in a Galati padded case and shoots rings around every AR-7 I've ever owned. Functions a lot better, too.
It does look like a great idea, doesn't it? Don't know exactly why it didn't fly, but they only made them for a couple of years. Might've had something to do with cost that kept the sales volume lower than they would've liked, or perhaps there was some glitch in the concept itself that showed up with field use and caused problems.
Butler Creek seems to bring out new products and suddenly discontinue them a lot. I bought one of their "Light Varminter" outfits from Cabela's and put it on one of my 10/22's. It works wonderfully; substantially lighter and much better balanced than any steel 0.920" rig I've used and every bit as accurate with its preferred loads. It went away after less than two years.
The most likely answer I can think of is that if a product doesn't meet or exceed their desired sales volume figure within a very short time, it's history.