the rabbit hole of Italian Proof House Date Marks

Oh and Thank You Garrett for the revolver, holster, book and CAPS!!!
their channel:

https://www.youtube.com/@UCZW1XuaZrR92BhXE09AOd5Q

Italian Firearm Proof Mark Date Stamp

Italian made guns. ALL Italian made guns must be proof marked. The Proof houses have developed and use a code to describe what date a weapon is made.
This is handy to know if you have a Italian made reproduction of a Colt black powder revolver

For the most modern list I could find online showing them from 1997-2017 see
https://www.shootinguk.co.uk/guns/proof-marks-and-re-proofing-a-gun-2272

for a list 1945- 2010 see this
https://unblinkingeye.com/Guns/IDC/idc.html

another excellent guide:
https://blackpowderarms.com/date_chart.php

this is an excellent discussion on the subject only their table only goes to 2003
http://www.powderhombre.com/mbpproofmarks.pdf