wiring diagram needed

I wanted to see if anyone would have access to a wiring diagram for a nesbit rooftop unit of the following model number RSV6005ZZZZHHMB0000
Serial number 80024B5498
From what I understand the company that makes these units are no longer around, and the units were produced in the late 70's early 80's. We have inherited a job that has six units of the same model number without any type of wiring diagram in sight.

Thanks to all