Need help with condenser/date

Specific Inspection Topics Inspecting HVAC Systems
1

Unitary Products Group, Norman OK

S/N WELM031393 & WELM031391

Charlie???

2

May be out of the ball park but off the top of my head E= May L= 81 or 02

I am thinking Unitary is a York product

3

Thanks Charlie, House was built in 1989
Never saw one of these before and now I’ve seen two!!!
No labels on the covers at all just on the serial tag.