Thats sort of a tough one to answer. Waterman made several different size nibs over the years.
Speaking in broad terms, Waterman nibs will generally swap in and out of various models with little difficulty. Pens like the 52, 3, 32, 94 and the like with nibs in the common #2 size will swap out with little or no problem.
Pens like the 100yr, crusader, commando, 54, 56 & larger size nibs like that will also swap out fairly easily.
If you have a model vs model example I can give you a better idea if it will work or not.
Dennis
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