I would if I were your customer.
Well Smitty... You would be MUCH different than my normal customer. I don't know if I've seen how you sell pens (I think of you more as a vendor than a seller of pens, even though I assume you do).
My normal customer... Many of them don't even know that my custom pens take normal refills until the ask or I tell them... And when they do they are familiar with the name brands (like parker or cross), but typically don't have a clue about Private Reserve. (Fountain pen users are an exception, but we're not talking FP in this thread).
My personal experience with customers is they get drawn in by the looks, then how they write seals the deal.
To put this another way that I am somewhat of an expert at (like you are with pen materials)... Lets say you were buying computer ram from me.. Do you know what bus speed your ram is? Do you use DDR2, DDR3? Dimm or Sodimm? If I completely lost you, don't feel bad.. Thats the way many of MY customers are when it comes to pen refills. I need to tell them what they need based on their questions - they don't come to me with the exact thing picked out.
I don't know where your customer base comes from, but in my experience selling.. the ONLY customers that know exactly what they want when they walk into my booth are experienced fountain pen or other collectors. (and I don't see NEARLY enough of those to keep me happy). I sell to people who like the pens for what they look like and how they write - almost none of them walk in knowing exactly what they want.
-----------------
All that aside - I'm sorry for taking this off topic... Back on topic.
I don't know if there is a vendor that carries them here or not, but another "brand" that I have heard of but not tried is Visconti... they make a parker compatible in .5, .7 or 1.0mm... You could search for them and see what you come up with.