Really hard to say exactly, it would depend on who painted it and what finish type were looking for or familiar with using ...
If they were just looking to do a 'down-and-dirty' quicky job - then they might have used an inexpensive Acrylic (Modified Alkyd) Enamel type paint.
This is the common "Earl Scheib" paint job you see advertized by local 'cheapy-repaint' shops
If they were somewhat concerned about replicating the OEM finish then they would have used a more expensive Acrylic Lacquer finish.
This is the type of paint you would expect to find in a more restoration or smaller volume shop.
I have used common paint remover/thinner intended for Enamel paints to 'test' for finish type before - but, you need to know the caveats (what-if's
) of doing it to really judge the outcome.
If the lacquer is oxidized, then it will rub-off color - just like an enamel paint would react to the solvent action of the thinner ... Makes it very hard to tell
I think it would be safe to assume it was lacquer if the PO can confirm it wasn't do by a 'cheapy' paint shop - maybe ...
If you try to use an 'Eraser' wheel on Lacquer it will heat the paint surface and cause the paint to 'melt' and damage it.
That said - almost any striping done after the initial paint job was most likely done with a Enamel Striping paint. So it should be able to be removed with enamel thinner/solvent
I would recommend you test a small area of the stripe (in as inconspicuous an area as you can find) with a clean rag and some enamel thinner to see if it comes off.
If not try a little lacquer thinner and see what happens ...
I've also had some success in removing stripes and other 'beauty marks' on vehicles by very carefully sanding them off.
NOT and easy procedure and very hard to do correctly if you never tried - but works well for me.
You then need to polish the paint surface back to proper gloss - so it's a pretty time consuming operation ...
Hopefully Scott, Martin and others that may commonly do this in the field will chime-in soon!
They may have a secret method this old man doesn't know of