.....

 

It is my understanding that IF an I-6 car has a shroud, it is an indication that the car had been a factory A/C car, but some I-6 cars (a few) without had factory A/C came with shrouds as well.

Besides, really it is an easy thing for a person with overheating issues to have thrown a shroud on that car at some time over the past 40 years.

Avoid reading too much into the "mystery shroud".