While hard to tell precisely, it seems missile's dimensions are around 2.9 meters long and 160-165mm in diameter.
We really have no way of knowing anything about development process of pl-10. Maybe it started with a pl-8 body from the start. Maybe those early design sketches were as wide as this missile. Many current gen wvr missiles have 160mm-ish diameter. R73 family, python family, asraam, a-darter. Those with smaller, 130mm-ish diameter are aim9x, iris-t, aam-5.
It is interesting that the designers seemingly chose both tvc and fairly large and radical control surfaces. I would personaly like to see some gas powered controls on the first half of the missiles - but that'd be a first in the world for this class of a missile so perhaps that is too radical. With current gen electronics and miniaturization it is realistic to expect this package to retain current generation range - 30-ish km under optimal conditions, but with very good maneouverability. I guess speed would suffer a bit more due to larger control surfaces, compared to similar missiles with smaller control surfaces, but that is usually a deliberate trade-off. Strakes on mid body also suggest more of a slower, coasting flight profile. "slower" being here a relative term. mach 2.5 to mach 3 is still pretty darn fast.