I got this set yesterday and it's pretty nice. Despite being aimed at the M51, there is no reason why it can't be used on the M50. Pretty much everything included is generic Sherman/IDF stuff.
The set has a bag of resin parts including spare track links, tool boxes, .50 MG, hull cable and wire brackets, jerry cans, loader's hatch, etc. There is also a selection of little resin rods to cut the various spacer pegs that fit behind much of the stowage. Some of this might be better made using plastic rod though?
You also get a bit of photo-etch with the frames for the spare track links, periscope guards, tool brackets and equipment ties, "luggage rack", fuel filler cap chains, fender braces, racks for jerry cans.
There is also some supplied brass rod (to make a pry bar from) and some softer wire. A few parts require bits of plastic rod (not included).
Instructions consist of two pages of color photos of the accessories glued in place on the Tamiya M51 kit. You will probably need to look at additional reference photos to figure out how some of the stuff goes. A bit of the work is tricky, like bending the ends of the springs, and their loop connections, for the loader's hatch springs from soft wire.
Not a super comprehensive set but it gives you enough to spruce up the Tamiya kit without going "whole hog". The jerry cans and racks are attractive. I paid $27 USD for the set from Lucky Model.