Okay, so I've got a rough idea of what I'm looking for, and I'm really hoping someone here can help me out. I'm currently renting an older, midwest home (built in the late 1920s I think), and all of the storm windows have these small, white plastic "slide locks" on the lower right and left corners that you "slide" towards the center of the window so that you can raise it up. Releasing the locks to have it click into a notch to stay raised.

I've been searching my local hardware and "big box" stores to try to find replacements for these things because about half of them are broken (and the landlord doesn't seem too concerned). The closest thing I've found is something like this: http://www.reflectwindow.com/product/6394531/473670 but it doesn't look 100% the same. So... Can anyone tell me what these things are called, or where I can find some to buy and put into the storm windows to fix the broken ones?

Thanks!