Wilkinson's Screw Grip Fore-end Fastener is the oldest of the common three, and is by far the most positive, durable, and trouble-free. You described it as "a Rigby swing lever". Patent was originally Wilkinson Sword Co.'s (you know, the razor blade people), Rigby apparently purchased it later.

Anson's 1872 push-button design ("my Webley a push rod design") came next, and is the next best. Reliable, but on occasion the threaded stem has been known to turn out under heavy recoil, locking the fore-end on the gun. Getting it off requires removing the wood from the fore-end iron with a chisel. Good design, but not as ideal for a DR as the screw-grip lever type.

The Deeley & Edge design of 1873 ("a pull out lever") was both the last and the least. I've had this type on a number of double guns of various makes, and have never had anything but trouble with it. Of course, this is the one that Merkel, Searcy, Heym, Krieghoff, and Chapuis all use on their double rifles. I gather that the parts for this type must be available in quantity really cheap.