When I first started restoring vintage fountain pens, one of the first questions I had was “how does this one come apart?” Photos like the ones below helped me a lot.
In some cases, these are photos taken just as the pen came apart, before cleaning…
Matador 76 “Oxford Everdurable”
Montblanc 22 (Note that I did not dismantle the piston.)
Montblanc 24 before cleaning (Note that I did not dismantle the piston.)
Montblanc 224 (Made in Denmark)
Montblanc 244 (Made in Denmark) Note that the piston cylinder is still inside the barrel. This is basically a tube with a circular hole and a small pin that fits into the groove in the piston shaft (visible in the photo) to keep it from turning.
A close-up of the same Montblanc 244. Note that the small washer at the base of the screw is a split washer. There is a notch taken out it to get past the pin when inserting it into the barrel. You may also note that the piston shaft has been slightly twisted. This is due to a little too much muscle being applied to it sometime in the past. It should be straight.
Parker 45 (For instructions on how to dismantle a Parker 45, see this video.)
Parker 65 mk 3. The nib and feeder on this pen MUST NOT be unscrewed from the front. The collector (in blue) must be unscrewed using a special tool from inside the pen (see this page for more information). Rotating the nib and feeder will break a small tab that aligns the assembly in the writing unit. Note that the connector shown in this photo (the threaded brass part on the lower left) is a replacement part – not the original
Parker Striped Duofold Junior with the Speedline vacumatic filler. The sac is about to be pushed onto the plunger with a special tool called a pellet pusher, and then folded over. Richard Binder has an excellent description of how to replace the ink sac on a vacumatic on this page.
Penol (and Christian Olsen)
John Bull “Special” (Probably made by Christian Olsen in Copenhagen. Note that the clip and finial are missing.)
Penol Ambassador Senior
Sheaffer Triumph Lifetime No. 1000 (See this page for dismantling instructions)
Summit / Curzon
Watermans 515D. Note that the D is a button filler variant. The normal 515 is a lever filler. Typically, the 515 has a friction fit section, but this 515D has a threaded section, as can be seen here.