I believe that in addition to the issued Model 94's, they issued some type of Scoped Remington 700 to "sniper qualified" officers mostly with the Tactical Services Section (TSS). This was well before they started a SWAT team in the late 80's.
I think there are so many Model 10's in good shape out there because so few officers carried them. After a year many of us got something better. A lot of model 25's and a lot of 66's. The department didn't take your model 10 back when you got your own gun so they tended to just sit on closet shelves for the next 24 years or until they were turned in after transition to Glocks. I'm sure someone made a ton of money "acquiring" the department's history whether it was photographs, guns, call boxes, badges, etc.