I tried to draw it in autocad but had forgot how to use and find all the functions and tools needed to make it look good so I just made a crude drawing to illustrate what I'm thinking of.
http://i127.photobucket.com/albums/p136/odderling/Locks/24032010114.jpg
(Key goes in from the right)
The keyway is supposed to be a pain to work with because of the round edges.
It's supposed to have pins in all the corners pointing towards the cylinder so that will be four lines of pins, all together 24 or 28 pins.
It also has two cylinders the first is just to make it difficult to pick, so if you pick the first pin it just rotates and you haven't accomplished anything and have to re-think how to apply tension.
Probably a bad explanation but I've had little sleep and alot of coffee

Any thoughts?