Comparing transparent production bricks found in Canada with milky white BASF “number only” testbricks. They seem to be identical except for the mold pip location which is on the opposite short side.
I think this confirms the theory that this BASF test mold was made from elements of an older production mold. It looks like elements of a production mold of 24 bricks were reused to create a test mold with 16 bricks.