Mortise lock

Thanks for writing in. Hm, the diagram in your first photo shows a mortise lock with a 90 degree keyway. Is that what you need? It's a very important detail. To clarify: the 82-223 has a keyway that is 90 degrees, whereas a lock like our 82-218 has a keyway that is 45 degrees. I'm afraid the sticker won't tell us what you require.

Can you give us the size of the oval hole that accepts the mortise lock, and the hole spacing as well? Many thanks.

Well, like I mentioned, if it's a 90 degree keyway then you're looking at our 82-218. That's definitely an important detail to confirm, but without an original to have on hand then your only option is to try one out.