I took a few. I have the info - number, year, weight, inspector. I'll get more photos later this week. I posted some on the Greybeard Outdoors BP Mortar and Cannon forum.
There is no breach block or any of that, just the tube and stand.

Re the only know example to explode during the ACW - was it maybe a quick fuse on a shell and it blew before it exited the barrel? That is my supposition.