No, it must be a new resin, Pete. For one thing, it has no apparent odor, plus it's white. It's very dense... and heavy! I first thought it was Hydrocal, they were so heavy, hard and dense, but I could at least scratch Hydrocal with an X-Acto blade with little pressure. Not this stuff.
Anyway, I went ahead and tried what was on hand, the standard 230-tooth blade I was using for plastics. Ran it at the lowest speed, and took very shallow cuts. Anything more than "shallow" would flex the blade and bind.
I needed the precision since I was cutting out just a single row of "bricks". It worked OK, and CA was good for splicing. As soon as a couple of patches where the blade wandered are filled and painted I'll upload a pic. I think the end result will be good.