Asking for some help from the Parker experts out there. I recently purchased this pen:

ImageUploadedByTapatalk1402156105.169830.jpg

And it has a date code of E which would be 4th quarter 1988 but according to parkerpens.net the international size duofold came out on April 1st 1989. How does that work? Would they have made it that early before launch? Or could it be a prototype?

Thoughts? Thanks!

-Gerald