How can writing instruments from an attic find — including a Montblanc Meisterstück L139, a suspected Parker 51 and an Omega — be identified and assessed?

The 139 is a variant with long sight window and steel nib, which marks it as a war model; war models are less valuable than regular 139s with gold nib but still count as collectable. The unknown pen No. 2 was identified as a cheap pen of the 1950s without collector interest, No. 3 as a Kaweco Omega 650, No. 4 as a Parker Aerometric of the second generation from 1949 with Lustralloy cap. For detailed questions on the Parker 51 the forum penexchange.de is recommended. Before sale it depends on the target group whether to restore: dealers prefer unrestored, end collectors restored pieces.