Pretty nice find for the price.
I've owned 3 (non M&Ps) S&W pistols.
Used model 59 , total junker..
new 645 shot like a champ.
Also, a Used 1076 that was very sweet but like with my SIGs,
I hated the de-cocker lever.
I've read a bit about the LAPD and others carrying the 4506, ect..
Duty loads back then ranged from 185 gr. Remington, to the infamous
SPEER 200 gr. Flying Ashcan JHP load.
(The same load I carried in my 1911 as a Deputy)
Always thought that they would deliver better stopping results,
but they generally got the job done.
Since I carried a issued 92FS Police Special for a number of years,
the flapper safety levers wouldn't bother me a bit.
Enjoy your new Smith .45!