Hello, thank you for posting,
The first few photos resemble the 39-226 handle with a 5/16" hex. However replacing the handle alone may not fix the issue. When these handles fall out, its usually because the collar in the operator hole has stripped. The handle may actually be in good working condition; in most cases, its the operator that is broken. Although, it does appear that the metal hex on the actual handle is damaged, so the handle may be the issue.
Please review to see what you think! If you think the inner collar of the operator is damaged as well, there are two options to consider as the collar cannot be repaired or tightened.
The first option would be to replace the full operator along with a new handle. To determine which style of operator you have, we would need to see the window open where we can view the arm attachment(s).
The second option is to use glue or even scotch tape on the handle stem to pad it out and help it "bite" into the operator hole. This is only a temporary solution that may only give you a few extra years of usage, if you are not interested in replacing the full setup at this time.
For the second handle shown, it appears that the operator has a 11/32" diameter metal spline that the handle fits onto. Please take a look at the 39-114L or the 39-205 foldable handle.
Please review and let me know if you have any additional questions!