Assuming Visconti Rembrandt Sections Are Interchangeable?

[mbankirer]

I just received a Visconti Rembrandt Eco-rollerball and would like to get a (fine) FP section? I assume the sections can be interchangeable?

Where would I find just a section for sale?

[cjr]

I recently purchased a Visconti fine point fountain pen nib for my Rembrandt Eco Rollerball. Unfortunately, much to my dismay, I discovered there must be two models of Visconti Rembrandt FP nibs depending on whether you have an Eco Rollerball or a Fountain Pen. The problem is that the fountain pen version is about 4mm longer than the Eco Rollerball version fountain pen nib. I have not found a store where I can buy the shorter fountain pen Rembrandt nib, although I have been told by others that Visconti actually sells a pen set with interchangeable rollerball and fountain pen nibs. If you find the shorter one, please post it here so others can buy them, too.