Does anyone know if the nibs on the Hero 616 are interchangeable with those on a Parker 51 Vac?

I've just bought quite a rickety, capless 51 on ebay, thinking I'd have the Vac repaired and borrow the cap from my 616. But maybe I could just swap the nibs?

Any advice appreciated.

Regards,
Eric.

As I remember, I believe the 616 and 51 nibs are indeed interchangeable (also the 132, as well as the 100, if you bend down the locking tab). Otherwise, one source of 51 nibs is Ernesto at Parker51.com:

http://parker51.com/gpage.html

$10 for octanium, $20-$25 for gold, postpaid. No relation, just a happy customer.

Thanks Nihonto. I did notice those nibs on my travels after I posted the question, although to my great relief they cost more than the potential-donor 51 nib. I am now thinking of all kinds of elaborate ways in which I could combine the two pens to approximate the 51 I am too "economical" to purchase. I fear this may cost me more in the end, but I live in hope.

Regards,
Eric.