Roger, I cannot see fenestrtions in your plant but I guess that it has small ones hidden under the synsepal (typical in manzurii) and the rounded staminode is also a good sign.
Probably I am not the best one to say if your plant is a true one because I am becoming more and more skeptic about this species... if yo read the original paper you will see that they do not give a key do separate it from schlimii. I would guess that the fenestrations (actually lack of fenestrations of small fenestrations hidden under the synsepal) could be used but IMHO manzurii is going to fall from species status soon or later.
In the schlimii complex you can put a very sharp line between fischeri, schlimii, andreettae and anguloi but it is very hard to set a border betwen schlimii and manzurii.
Sorry if a am generating more confussion but this is what i do think right now.