The middle seams look good, just make sure they are nice and smooth and even with the top of the grates. The sides look like they may be a little thick. It probably isn't worth worrying about right now, but when you start it up this fall, pay attention to how the burn pattern looks. If the coal along the sides of the rails are getting hung up by the cement, you won't have a nice straight burn line running across your bed. If this happens, you may want to shut down and shave some of the cement off. Better to be mindful of it early on and take care of it before you really need the heat later on.
While you are at it. Did you notice an accumulation of raw coal under the stoker when you cleaned out? This is also a common problem. If you look at the back of the grates from the back of the stove (where the hopper sits), you may see a gap between the grate side walls and where the stoker mechanism is inserted into the stove. This is not a defect and many folks (including me) have just filled that gap with cement. Again, keep it nice and smooth and in line with the inside of the walls so coal doesn't get hung up on it. Not a big deal, but that gap does let small pieces of coal fall below the stoker into the stove.