As it turns out, the repairs I made to my mold yesterday morning took and the mold is very close to "perfect". It hard to accept anything short of "exactly what I wanted" and balance that against something that "works". I want to think that the imperfections in the mold give the cast pieces "character", but I find that to be difficult to sell.
My son must be as cheap as I tend to be. When I asked him what he would pay for one of the castings, it was like pulling teeth to get him above $5; I'm thinking of asking $15.
I managed to get three casts last night and two more before leaving for work this morning.
My son used the first two casts I made (which I wouldn't sell because of shrinkage making the edges very thin) as templates to make a 90 degree corner piece. He was laying the tile for the decking when I left for work this morning; I asked him to wait to pour the mold so I can take a final look at the original and make any tweaks that come to mind.
We were talking last night and I am thinking of donating a set of the terrain pieces to my local gaming club to be a prize at the next tourney. I'm not sure right now what I am going to consider "a set" - a minimum of 4 straight pieces (each is 5 inches long), probably two 90 degree inside corners (I think they will be 4inches by 4 inches) and two 90 degree outside corners (I think they will be 5 inches by 5 inches) - I THINK a GW Bastion will sit inside of that, I need to check.
My son thinks I should cut the length down. Each straight piece has crenelations that give 3 firing rests. If I cut one down to just one positions it would be about 1 2/3 inches long, two positions would be about 3 1/3 inches long... Those sizes would work better with smaller angled corner pieces to make a snaking defense line but would be easy to knock out of position. If I had a wide blade on my band saw, I wouldn't have to make a new mold for each size...