Some help please - When was the first Parker ink cartridge made.

[proteus]

There is very little accurate information available to answer my question.

I thought the 1960 Janesville Parker 45 Colt was the first pen to use a Parker Ink cartridge.

Know that the first ones produced at Newhaven were in 1962.

There is a reason for my question - I am attempting to date a pen.

Many thanks.