I recently purchased a Parker Parkette based solely on the photos provided on eBuymyjunkplease. It wasn't an expensive pen, and the nib appears to be intact. The pen needs a new sac.....and a new j-bar. The sac size was easy to determine (thank you, FPN!). The J-bar length appears to be a mystery. Looking at some websites, it looks like the J-Bar comes in 62mm, 54mm and 40mm.
Any ideas on which one would fit in the Parkette? It's a 1938 Junior model (not Deluxe) in grey celluloid marble. The nib is steel with a little gold plating left and the number "9" stamped in it.