Stronghold Terrain previewed these a little while back and now they’re available for sale.
From the update:
The Stone Wall products are now available.
Take a look at our Online Store.
Stone Wall Set: three resin wall sections plus four resin columns and three plastic fences (€9.90 EUR). Together, they are 28.5 cm long and 4 cm high.
Expansion Set: one wall section plus one column and one fence (€3.50 EUR). 9 cm long
Damaged Section: one wall section and one fence (€3.50 EUR). 9 cm long
Your Stronghold Terrain Team!