I happen to have a spare folding stock for a mini14. I'm not sure if it will fit the newer ones. Mine was a 183-series bought sometime around 1982. It is called the F1A2 by R&R Enterprises. It was the highest quality folding stock I've ever seen for the minis. Made of some very strong carbon fiber type material(?). Has a side-folding stock styled after the folding FAL stocks. Very strong and positive locking with push button release. The folding assembly is all steel and very fast and easy to deploy.
I gave like 130.00 for it way back in the early 80's. Sorry I can't post pics but I can email them if you want.