I'm so used to wide Pelikans, Lamys Parkers etc that the Simplicity F nib was a shock because it was so ...... fine! Nice and smooth, perfectly delightful in every way except a bit thin for me.
I'm in the UK, but sending the nibs alone would be so light and hassle-free that this needn't be a problem.
A long shot, probably - but worth a try
John