I believe I'm correct in thinking that Derek Warner has "proper" chain and sprockets for the drive system on his model of Decoy.... Am I right Derek?

Can you tell me where you got it, what size the chain is, what shaft size the sprockets fit, and if it's relatively easy to adjust the length of the chain without specialised tools?

I have an idea for a project, but because the chain drive would be fully visible, it needs to look "right".