Hi Ciro,
I am far from an expert on the T-55, but am also building a Taliban version of one at the mo.
In looking at the available reference pics, the conection for the canvas cover does appear to be a thin steel strip and so could be damaged as you show. However, im not sure exactly how it could get damaged like that as I doubt debirs or small arms fire would do that. Perhaps shrapnel, but for both sides it would be a little strange. It may be more realistic to show a full 'strip' but bent out and only connected at one end?
Good luck with your build, its looking very inprerssive so far!
James