First off I will say that the model looks great. Nice job on the weathering.
Now, if the is a depiction of a 1990's M51, there are a few things that need to be on this tank that Dragon does not give you in their kit. Firstly, there should be a little box that is fitted just behind the TC on the side of the turrent. Secondly, the storage shelf on the back of the should be a large box, like the one in the Academy kit. Thirdly, the TC MG should be mounted on a scissors mount.
All that being said, I am no expert, and there are others out there that have better info than me, that might prove me wrong, which is good then I can also learn something new. And I am in no way picking apart your build, it looks great. There are just some items that Dragon in their infinte wisdom decided to leave off their M51. In order to have the best references, a person needs to get Tom Gannon's book on the shermans in Israeli service. Just my .02 cents.
Scott