Though this is not a complete pen, this is not the typical Montblanc 149. This vintage pen is made primarily of steel and not resin. However, the ink window and finger section holder are likely resin or plastic. You will get the cap, finger section holder(needs a new adhesive sealant to keep attached), barrel, and complete fully intact working piston mechanism (rod, plunger, twist turning knob).
The three things that are missing here are the nib collar, gold nib, and feed. The Montblanc store may likely be of some assistance in helping to complete the pen of the three missing parts. The item "Vintage Steel MONTBLANC MEISTERSTUCK 149 fountain pen used for parts good piston" is in sale since Saturday, December 22, 2018. This item is in the category "Collectibles\Pens & Writing Instruments\Pens\Fountain Pens\Montblanc". The seller is "antiqueboi" and is located in Aurora, Illinois. This item can be shipped worldwide.