This is a sleevegun I just made based on the old Wild Wild West one that Robert Conrad used. I remember the great pictures everyone had posted a while back from my original sleevegun. This one is based off of Indy Mogul's and thesonofabob quick draw rigs from youTube. It works like a charm, and I can attach anything to it from derringers to wooden stakes.
It's made from an old drawer slide, a couple of springs, some L-brackets and an aluminum tube to hold the monofilament release.