I can remember when Rotring first started producing “regular” pens and pencils, rather than draughting tools. Mid 80’s In think.
The first they produced were an aluminium pen and retractable pencil in the style of their conventional automatic pencils. I bought a set (not cheap at the time) but they were lovely to use.
The 600 range came a little later, and you’re right, they are beautifully made. The originals were German made, and the range included a fountain pen. I didn’t buy one, as I was into more traditional pens at the time, but I regret not doing so as Rotring did a superb job on them, and they became a modern classic.
Rotring was bought out however, and many of their lines were dropped. The range of drawing pens was reduced, many drawing instruments were dropped or cheapened, and the rights to the “Aristo” navigation instruments were also disposed of.
The 600 series continued though, along with it’s similarly numbered relatives. The pens and pencils today are produced in Japan (which I suppose gets us back on topic) and I have to admit they are still of very decent quality.
I generally use a pair of 600 series ballpoints at work (with Schneider “slider “ refills).