Gary, please correct me if I am wrong, but I thought the fan cover and the one next to it (I cannot remember what it is for either) were sort of optional...I have seen pictures of them completly missing, but it may just be for light maintenance.
I have ONE photo of a T-55 in what looks like Chechnya without either cover and all the photos I have of the T-55M5 show it only having the right hand side cover attached (And open).
Any thoughts?
(Also, I agree Ciro, keeping all of your comments about this build in one thread would be a better choice.)