Let me start by saying thanks for a great and extremely informative forum.
So much helpful information. Well done.
I have recently been playing around with some old ducs that my brother and I acquired about 15 years ago.
They have basically been sitting in a pile since then, in a back room of my fathers garage in upstate New York.
I live in Brooklyn and have finally gotten to a point where I can spend quite a bit of time up there playing around.
I convinced my father into letting me build a little shop area in the 3rd bay of his garage.
Tore a wall down, which required moving all the old duc stuff, and extended it back some to make more room.
As I'm going through it all I realized that I really like these bikes. So have decided to finally do something with them.
I don't have any experience in vintage stuff but have a basic background with mechanics.
So I am learning a ton by just playing around and trying to soak up as much as I can from forums like this one.
There are 4 frames and several motors in various states, along with a 99% complete 1964 90cc Mountaineer.
Not a desmo in the bunch, but some really cool stuff.
These old motors are absolutely beautiful to look at. Kind of jewelry like in some aspects.
I am having a great time going through it all, cleaning some of the engines up and just generally tinkering with them.
Just wanted to introduce myself and say thanks for all the info here.
I'm sure I am going to have a lot of questions in the upcoming rebuilds.
I'll try to post some pictures, if I can figure out how to do it. I'm better with bikes than I am with the internets.

Cheers.
-karl