When were "fishhook" hammers used on M&P's, post pics if you have them

[VM]

No. Posted the question a few months ago. Nobody knew.

There's no apparent difference between the "2" and two "4" marked hammers I have.

Thanks.....

 

[OIF2]

I've posted this before, but it's a nice one.
Bob

 

[Belfastman]

I have 1957 k38 combat masterpiece that has same hammer.The serial number is k3086xx. It also does not have model 15 in crane area,so it had to been at time both were going away.