Night vision/ Infrared systems

[JohnAbrams21]

I am setting up a scenario set during the early 1980's. Around 1981-83 to be exact. I want to give some of my units like Medium Machine gunners and automatic grenade launcher units a night vision capability. What numbers would be realistic for this era?

Would equipment like the AN/PVS-2, AN/PVS-3 still be in use at this time or would later units like the PVS-4 be in use? What number codings would be appropiate for these types of equipment?

Thank you for any help!