the" B " pillar is fine, I can see in your 1st photo it has the internal bracket their for the pop out frame... only late type's ( 72/73) and oddity models ( aussie RHD ) did not get this bracket in the body nor the screw pad for the latch ( it can be weld in later ) but thats not your case here...
for your problem the solution is pretty simple... originally there were plastic seals that fit over the tongue on the pop out frame, this fitted the hooks on frame snug to the body, what happens is the 1st time the pop out is removed, these seals stick to the body and fall down the B pillar lost in the B post of the car,
NOS is one solution, but this small item is very rare and hard to find... the simple fix we use is black electrical tape... you wrap the hooks to create a soft wrap that will mimic the original seal, and being tape you can fine tune the stiffness of the seal & hinging point with more or less wraps of tape...
reproductions on this seal are on our "TO DO LIST " hope this info helps...
Anthony / ISP WEST
also anyone that needs to see a before / after on a Type 3 missing the pop out brackets... here u go...

