Fencing Gravel Boards Available?

Any chance anyone has any spare concrete gravel boards for fencing available? Like this one. 

1ft x 6ft or 300mm x 1.83m.

Cannot seem to be able to get hold of any locally, and I could really do without a trip to Romford to go get them. Happy to buy them from you. I need 2, as I luckily have one floating around...