Thanks for the help. Someone on the Dahon forum showed me a Trek seat post QR that was similar to what I needed. The biggest problem with most seat post QR bolts is that they are only threaded at the end. I needed something that had much more thread. I went back down to the LBS and got lucky to find one of the mechanics. He went through their used parts bin and found one that will work. I will have to use a few stainless washers but it should work great.
Actually I am in the US (Savannah, GA). In our neck of the woods I would call it good ol' redneck engineering. I heard one of the brits use the "bodge" term, so I picked it up as well.
I will post pics of the finished redneck engineered bodge later.