I've known about Owosso Model 2s, but I didn't know Owosso had Thunderbolts. Speaking of Owosso, there are a couple of locations that may interest you. There is another Model 2 across the street from the 2001 on Chipman and Oliver, and there was a Model 2 that was removed (or fell down) at the corne...

Have a low mounted Model 5 in Lupton, MI

Update 2: I need some opinions. I not sure how I feel about this evidence, but I wanted to share. I may have found the location of the St. Joseph Hurricane. I feel the evidence is a bit shoddy, but it's worth showing it.

Address: 2600 Niles Rd, St Joseph, MI 49085 - The Shell Gas Station

Update 1: Found some more locations in Oak Harbor.

Coordinates:

41.535812, -83.125846
41.590265, -83.164427
41.542731, -83.042226

I did some looking around near Davis-Besse Nuclear Power Station as I was curious about the location of the Hurricane in the newspaper and I found something interesting. The 2001 is located on W Lakeshore DR. & Henry J Buhrow's Pl.