I've restored a Swan pen which had a feed with an immencely huge gap. The feed has "SWAN" engraved on it, and is a good fit in the section, but I've heat set it several times and it keeps going back to making a gap, enough to put paper between the nib and feed (not as big as originally found but still big enough to cause leaks).
I almost thought it may have been replaced at some point and that this may not be original feed (or nib) for this pen, but it's all Swan and the fittings are the same. I don't presume they had differently curved nibs or feed across the models of the same size.
What is best to do?