Unidentified Hardware

I am at a loss for this window hardware. My parent's house was build by a contractor that used "industrial" parts that are so irregular that it is often hard to find parts. It was build in the 60's. This being a prime example of tough finds. I am looking for any help...hope you're up for a challenge. The only marks are what looks to be an L with a Z inside it(best guess) and a K inside a spade (along with the RH for the right hand). I tried to take pics of the two tiny markings.