Orion-15 Aperture Question

I've been asked by a good friend to sell some Leica thread mount Russian gear. One of the lenses is a little Orion-15 28mm F/6 – I'm aware this is a rare item. I'm puzzled by one thing about the aperture, and would appreciate some advice – the seven blades don't open fully when at maximum aperture. That is, they don't fully clear the area of the lens elements, disappearing when fully open as with other lenses. I've attached a picture to show its widest and narrowest openings. The aperture ring turns through its whole range, and the minimum F/22 aperture lookss reasonable. I can understand it being restricted due to the F/6 maximum, but I'd like confirmation or otherwise please that this is in fact normal behaviour.

 

I've googled it but can't find clarification of this point - thanks in advance for any comments.

 

Edited April 7, 2018 by John Seaman

I've now found some more pictures of the Orion, and they all show the aperture blades visible at F/6. So it looks as if my friend's lens in behaving correctly.