Hi Buntoro,
Very interesting pens. I had never seen a 275. Looks very similar to the 642 but with a different clip and nib. The cap ring top and cap ring are also different.
Interestingly is that the code number does not follow the usual MB coding.
The best illustration I have ever seen was made by Christof ( hope you don't mind me sharing this here).
I would add 6 and 7 on the left side of the magic triangle (6 - Masterpiece with metal cap and plastic barrel; 7- Masterpiece with metalic cap and barrel)
Example: Montblanc 642
6- Masterpiece with Metal cap, plastic barrel; 4- Piston filling system; 2 nib and pen size
But in Denmark we can find very interesting MB pens ( especially the coral ones) and even some "oddities" .
Congratulation on this find! This 275 is a pen a would love to own.
BR
Vasco
Thanks for the comments and ChristofZ's "Magic Triangle". Indeed, the numbering does not follow Montblanc's usual numbering system. I guess there must be some other Danish Montblancs that also do not follow this numbering system, otherwise this would make the 275 very unique indeed. Best, Buntoro.