I bought the Oil Cooler set-up back in the mid-80's. It was
manufactured by Lockhart. It is a Model YA-736. The thermostat is a model
BP-180, designed to open at 180 degrees F.

Lockhart made a cooler with a built-in thermostat but because of the tight
space to fit the Virago it required an external unit. For what it's worth,
being the pack rat that I am, I had saved the original box and the
installation instructions. Attached are a couple files I scanned from the
instructions. Don't know if this helps any since it was off the shelf but
let me know if you want any more of the instructions scanned and I can send
them. The application required modifying the plastic cowling around the coils.

"David Gadd"
82 Virago 750

Oil Cooler Thermostat