Thanks for the heads-up on this. I just ordered 80 pounds worth! I've had 16 2'x2' terrain boards sitting waiting for months, and was just about to start manually making sand-bags... These castings look great, and mixed with some scratch build elements will be just the job.
There are some very good items on his site and not just trench stuff. 45 sandbag sections for a tenner? Ten palm trees for the same? Looks like value for money.