Info Deckel FP2 Coolant Pump Chain

Hi folk

Sadly my FP2 was bought with the Coolant pump missing ... :angry:

So I'm just about to "Splash out" on a pump (Excuse the pun) and also purchase a new chain for the drive to the sprocket gear.

Can anyone advise on:

How the chain is sized ... do I need to shorten a NEW chain or is it correctly sized?
How tight should the chain be?

Thanks very much :)

John :typing: