Assistance Needed with Crank Handle Replacement

Hello!

I'm reaching out for assistance with replacing the crank handle for one of our windows. The current crank handle (please see the attached image) needs a full replacement, and the neighboring window is missing this part entirely.

Could you help identify the correct part(s) and advise on how we can proceed with getting replacements for both windows?

We did have someone that works in glass come and look at the window and we're informed that they "don't make these parts anymore" so I'm hoping you can help so we don't have to fully replace these vintage windows.

Thank you so much for your assistance!