Milwaukee Road caboose 991611

I am trying to locate Milw. caboose 991611 which was used on the St. Maries, Idaho to Elk River branch line for many years. My book "Milwaukee Roads Steel Cabooses" by Jeff Kehoe on page 39 just says "privately owned".

Anyone with any information please e mail me at:
            arl4102@blackfoot.net.

Thank you.
George Shattuck,
Missoula, MT