Joe, the pic I'm looking at right now show T-55s in the 1965 May 9th parade, and the following bits are white: the light guard (only halfway down on the rear sections), the top edge of that splashguard thingy that crosses the glacis under the light guard, the raised "ribs" on the front fenders, the side edges of the sponson sections (but not the front and rear "fender" sections), the rim of each road wheel, and the center hub of each road wheel.
All 44 vehicles visable in this pic are painted thusly, and all have the patriotic emblem with "CCCP" and other Russian, with the red star flag wavng on a background of laurel (or wheat, for all I know!) Those emblems were included in the Lindberg T-55 I built ages ago (not too bad for a Lindberg kit, actually! Or did they just re-release the Esci kit?), and more interestingly in a Propagteam "Russian Aces" decal set I found for a Russian I-16 Type 10 aircraft . There must be a bit of history behind that emblem, I reckon!
Anyway, hope this info helps.
Still no ideas on what's on the rear end? I'd bet there's nothing, but ya never know.