My 659 is one of my favorite h-guns (it was like many now appearing on the market an old carry gun by the local police, ending up in a pawnshop), the weight and large grip make it a great shooter for medium to large hands. I've had mine since 98'
Do yourself a favor and only buy S&W mags, the aftermarket models are absolute junk (I know from bad experience). The only thing to show any wear on the entire gun has been the mag follower. New followers are available from Midway USA, pretty inexpensive so good for your rangebox. Do yourself a favor and use only SS recommended grease (like RIG). Gauling can occur on the slide to frame contacts (SS wears kinda weird) unless you have a thin coat of an approved lube. Don't count on regular gun oil for the barrel bushing, side/rail contacts and frame to barrel lockup areas.
Uncle Mike's at one time had a rubber over metal grip set, awesome and feels great on mine.
Count yourself lucky to have one with the original wooden sideplates, I've been looking at g-show's and online for years and haven't seen any. Will likely have to carve mine if I ever want any.
My trigger had a grittyness to it when unloaded. Old dirt and grease.
Flooding the mechanism with 1/2 a can of carb cleaner followed by a good squirt of CLP (call me old fashioned) smoothed everything and it's got a nice pull.
If you've picked up the gun you're likely very happy with the purchase!
Happy shooting!