In message .com,
deano writes
Anyhow, the owner would now like the barrier re-instated using metal
(motorway style) rails, or something along those lines. Each bay is
just over 8' wide and needs to share fixings on each post with the
following bay, i.e. there are 2 holes per post, one above the other.

Anyone know where I can find such material?

Thanks,
deano.

Don't know if you're still looking but;

http://www.anchorsupplies.com/indi.htm

3 metre lengths for £10 each.
--
Clint Sharp