PAN AM Awning Windows

Hello - house built in 1959, original windows. Most don't close all the way, small gaps at the bottom and along sides. Trying to replace parts and hoping to get those to close all the way. Couldn't find a model #. Love the windows. Some cranks are hard, not sure if that means I should replace? I put WD40 but that didn't do much.

And if so, with what part? Any help would be appreciated, we love the windows would love to just replace some of the hardware with the hope of that operating better and close completely so the bugs don't crawl in.

Thanks in advance! :)