I have 3 external doors on my house. Each has a different key. Two are Schlage sets and one is a Norwalk. The Norwalk blank says AR1 on it, and the Schlages are the standard version.

The Norwalk is what I'm most concerned about. It looks vintage, and is a sash lock. Turning the key operates both the deadlock as well as the latch. I don't know if these two systems can be made to work with the same blanks.

I would like to do this myself, but am currently more curious if it is possible at all.

Is there a way to have all the locks share a common key?