Don I sent over a box for you to try your hand at and see if it does fit your Pelikan... feel free to post a pic if you build it up...
I have some pencils that came with pens, my coolest is probably the Sheaffer tuckaway set, very small but the pen is nearly regular length with the cap posted, about 1946 as best I can tell, pre '47 anyway as has the old "wire filler" vacuum. I was very happy also that the black parker 21 pencil had a date code so I could date the age of the pen-1954 (both are engraved with the original owner's name).