Will any other Parker cap fit a Parker 51?

[newkid]

My question this; is there any other cap in the Parker line that will fit a mijd-fifties Parker 51?

NK

[RobJohnson]

What year 51 do you have?

I have seen a 61 on a late model 51 but to be frank if you are in need of a cap for your 51 it is always the best plan to keep with the correct cap for the pen, they are readily available and not expensive, a WTB on here should produce results, many of us will have a 51 cap or two in our parts box.