Hi,
Yes, I have seen this before. The bridle is not upside down or backwards. The guy simply positioned the lock bolt to go through the bridle hole because he wanted to avoid drilling a hole through the bolster of the beech plug . He probably positioned the lock too far forward on the barrel thinking the vent had to be well out in front of the breech plug and then realized the rear hole would go through the plug if he located a hole in the lock plate bolster. For some reason he decided he shouldn't do that so he did what he did.
dave