I no longer own any guns from Boston P.D. However, I did have a Police Positive from the mid '20s in .38 New Police (aka .38 S&W) that was marked for them and a S&W Model of 1896 .32 from the Boston & Maine Railroad.

I do have PD revolvers that were carried IN Boston.

1) Colt Police Positive .38 NP from 1934 - Metropolitan District Commission

2) S&W Model 65 .357mag., Mass. Registry Motor Vehicles

Best,
Charles