Sheaffer Targa construction

I recently purchaced a few Targa by Sheaffer fountain pens on eBay and
discovered that the barrel threads seem to be plastic. I know that the
fountain pen parts are interchangable with the rollerball and I have a
rollerball with plastic threads but what I would like to know is did
Sheaffer ever sell pens like this? One seller swears that his pen was
original. I actually like the plastic threads so it's no big deal for
my personal use but if I ever sell one of these pens do I call it a
cobbled pen?

I have a lot of Targas in my pen collection.
First thing to remember is that the Targa was "redesigned" somewhere around
1990.

The original Targa had:
Narrow Gold band on barrel where it met cap
Narrow gold band at base of barrel
Brass insert for threads for section attach
Wide Gold band on cap above where pocket clip mounted

The redesigned Targa had:
Narrow Gold band on BOTH barrel and cap where they met
Wider gold band at base of barrel
Plastic insert for threads for section attach
Wide gold band on cap above where pocket clip mounted and narrow gold band
on cap just below where pocket clip mounted.

All of the gold bands are, of course, gold plated, not solid gold.
All of the swirl pattern Targas are the redesigned style.
The cloud/ronce patterns are the old style.

--Gary of Michigan