You have a SS version of the venerable Model 10 'M&P', heir to the throne held by the original circa 1898 .38 Special revolver. By the -4, we know it was made in 1988... and, being a 2"... if it is a DA-only (hammer won't cock for SA use), it is one of 150 made for Brinks. I have a 1/2003 vintage M10-11 in 2", so I can speak to the utility of the 2" 64. I would say you have the ideal snubby .38 - a six shot M&P in SS, no less! A call to S&W's 800 # (1-800-331-0852) with the serial number will reveal whether it is designed for +P use. A great PD round for it, if it can use them, is the Remington 158gr LHPSWC +P. I get 840 fps from them in my 2" 10. The 67 is similar, except for the added adjustable rear sight (The 10 and 64 have fixed sights.). Hope this helps...
Stainz