some recommended starting points. (many people seem to have had this issue)
TLDR in order of frequency of recommendation:
- make sure its clean (if it REALLY is a NOS this should not be a problem)
- make REALLY SURE it's clean
- are you ABSOLUTELY POSITIVE that it's clean???... maybe clean it again...
- use a wetter ink
WARNING THESE REQUIRE OPENING THE PEN and varying degrees of screwing around with stuff...:
- align air slits in collector with the nib
- nib work (tine spreading/flossing)
- nib/hood spacing issues
Also, I once read (but am now unable to find it) that some suspected that they would dry from the factory in order to help with the quick drying that people expected from a top tier pen that was supposed to "write dry with wet ink" Priorities back in the day were not necessarily on watching a nice wet patch of ink get laid down, but more on getting words onto paper and drying so they wouldn't smear.
My (completely non expert, absolute member of the peanut gallery) opinion: If this really is a NOS pen, and you REALLY are intent on using it (vs preserving it) then I would suggest using a wetter ink. That way you don't have to disassemble it. None of my "51"s are "gushers" most are medium/dryish in wetness. I guess it depends on what you consider "dry"
Good luck. Let us know how it turns out
Just give me the Parker 51s and nobody needs to get hurt.