I've been trying to find a straight answer on this but have been unsuccessful.
I need to replace the damaged hoods on a couple of my 1950s aerometric Parker 51s, but don't know whether to get the "recessed" hoods which have space inside for an o-ring or the non-recessed ones which simply have threading.
Does it matter which kind?
Do you have to replace a hood with the same type that was originally on the pen?
I'm hoping it doesn't matter, because I'd rather not take the pen apart to find out what kind it has.
Thanks for your help!