Vietnam # 4. NVA
North Vietnamese T-54 markings.
T-54B (or Type 59) and T-54-3.
The reference photo seems to have been colourised, so it is possible that the turret numbers actually was white, and not yellow as shown on the photo.
Update alternative B.
Previously misidentified as a T-54B tank, but it is an T-54-3.
