@ Suhiir - not a problem. i've put it on my "to do" list (P.196
)
@ Andy - even without my written sources, I'm entering the joust here. First, I haven't seen a single web source (and yes, I read Russian, albeit slowly!) that suggests that the PK version accommodated anything less than 20 pax. Secondly, I've attached a photo of the hatches on a PK - if one thinks about this logically, what can adding armour do to reduce troop capacity? Answer - not a lot. I've also attached (and I know this is iffy, but I Googled it in cyrillic characters, so presumably it's authentic) a photo of a modelled interior of a PK. Now, if the bank of 4 seats on the left take 2 bums each, far right takes 3 and near right takes 4, you end up with 15 - which agrees with nobody! However, if the bank of 4 takes 3 bums each, plus 4 plus 5, you're pretty close to 20 (plus 1 guy saying 'spasibo Tovarishch' for the extra room).
However, the seating layout is nowhere near what Michal suggests. I await a proper shot of the interior of a PK.
My 2 cents worth.
Richard H