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 or rope) for standard Openlock 1x1 dungeon fixtures trapdoors, traps, columns etc.

This corner adapter also works with the Spiral Corner Stair (http://www.thingiverse.com/thing:2125201 or http://www.thingiverse.com/thing:2125114) to help match up to the standard E tile dungeon layout or as the top floor penetration down to the spiral stair.

Kudos to Printablescenery for creating and sharing the OpenLock standard.
http://www.printablescenery.com/product-category/rampage-system/
Rampage http://www.thingiverse.com/thing:1821631
OpenLock 4.0 http://www.thingiverse.com/thing:1833963 and this design will still work with the new OpenLock 5.0 http://www.thingiverse.com/thing:2098287
and kudos to DevonJones Original OpenForge Stone Floor Tiles:
http://www.thingiverse.com/thing:171315
See here for the Printable scenery adapters to the OpenForge 1.0 style tile layout:
http://www.printablescenery.com/product/old-school-floor-adaptors/
Spartan782 remixed these stone tiles with OpenLock slots here:
http://www.thingiverse.com/thing:2064069