People may want to check this site out:
https://wwiiafterwwii.wordpress.com/
It highlights use of WW II-era equipment (aircraft, tanks, small arms, artillery, etc.) well after the end of the war. One example: Su-100s still being used in the Yemen War. Another: The huge arsenal found after the Grenada Invasion, and some of that was WW-II vintage. RDF Sourcebook users: Iran was still using Shermans and M-36 Tank Destroyers in the Iran-Iraq War (Some were found in Iraq after OIF), and still uses the M1 105-mm howitzer and the 155-mm M1 as well. Not to mention that StG-44s were found by U.S. and British Forces in Iraq (and some of the Syrian rebels also use 'em).