New Arrival and a question

[orfew]

So, I just received this pen. It is a wartime example of a 334 1/2. It has the incised lines where the cap bands usually are. It has a steel clip, not plated one. It also has a steel nib. I have inked the pen with MB black and the pen is a great writer. There is some good flex to the nib and the nib supplies some excellent line variation. The pen is in very nice shape. There is some plating loss on the clip but the imprints are nice and clear.

Now here is the question, there is what appears to be an 'o' or 'D' where the nib size marking should be on the blind cap. Does anyone have any idea what this marking means? I would appreciate any help. In the meantime here are a few pictures.

[Fawkes]

If its O I would assume its oblique, but I'm not sure what D means. I have a 136 transitional from about 1948 with an OM nib however the blind cap is marked with what looks like an angle symbol (∠).

[jar]

Is it marking or a pin?

[orfew]

Is it marking or a pin?

Hi Jar,
to me if definitely looks marked as opposed to a pin.

[CS388]

I, also, wondered if it was a pin, as have seen similar pins on some older Montblanc knobs.

It looks as if the markings (334 1/2, Montblanc, cap outline, etc) have been recently whitened - common practise with some sellers. Could the seller have mistaken a pin for a marking and whitened it, making it look like a marking?
Just guessing here. Have never seen the O (oblique) mark without a nib size next to it.

Besides all this - beautiful pen. Congratulations!
Much as I love the traditional white snowcap on Montblanc pens - I think I prefer the outline version which you have - the black snowcap?

Hope you enjoy it.