In article , John
writes
Many thanks for all the ideas. the concrete spurs sound the best idea.
Pity they don't sell full length concrete posts like the C. Council use.
The existing concrete is not flat at all but it's hard as iron and an SDS
chisel has great difficulty. I'll see how easy it is to get the old wood
stumps out, then ponder a bit more.

Visit your local Jewson, MKM etc to buy full length concrete posts. It
is hard work putting them in but you won't be doing it again.
--
Tim Mitchell