and where can I get them?
LZ sells a chain that is 13 links per CM about 32 links per inch for us Americans who are metrically challenged.
Flyhawk has their 1/700 anchor chains #710028 which I assume are quite small but I have not been able to dind dimensions for them.
The LZ chains are quite reasonably priced including shipping direct.
For what it is worth I am looking to find chains for things like attaching the pins that hold the spare tracks on Panthers.
Note: screwed up and put this on the Axis page too, sorry for the duplicate.
They have some 40 links per inch in either brass or pre-blacken brass chain. Any good model railroad store should carry it.