You said you wanted a challange. What is the problem?
The listing says it comes 0 bitted. That means if you put in a key blank, it will turn. Or if you take a straight backed pick, like a half diamond, into the lock with the flat end up against the pins and lift them all to the top of the keyway, it will turn.
That is a Yale LFIC (Large Format Interchangeable Core) core in a mortise housing. The last pin engages the lug that keeps the core in the mortise housing.
Gordon
Just when you finally think you have learned it all, that is when you learn that you don't know anything yet.
