OpenLock Adapter-Stone Corner

1st of the series OpenLock adaptors OpenForge 2 Corner Stone. I'll follow with the rest of the series here.
The corner adapter came about, because I needed a 1' wide catwalk/mezzanine and wanted to match the typical A wall on the outside. (thus the "notches" on the bottom to fit the corbel/braces in the corner for the murder holes tiles)

The design became useful in other ways as the corner adapter is good to integrate into the dungeon E style layout as a 1x1 floor penetration (with a ladder