I’ve owned a few Pelikans, the modern Souverans and some of the older pens, but I don’t really understand the range of Pelikans in the way I do with Conway Stewarts, Mabie Todds or even Watermans.
Take, for instance, this 500. Correct me if I’m wrong, but I believe it to be an upgraded 400, made in the mid 50s. A medium-sized pen at 12.6 cm capped, it is strikingly handsome with its gold-filled cap and blind cap. The barrel is green/black striated and translucent.
It has the nesting Pelikan emblem on the cap top and the traditional Pelikan clip. The gold nib is fine and semi-flexible.
There is a professional personalisation on the barrel. The gold is in good condition and shows no wear. This is a pen with a lot of bling but it is also eminently practical.
It’s a pen that you really want to write with. I’ve had other good Pelikans, early pens with very flexible nibs, but this is the best writer of them all.
Goodwriterspens's Blog 
Hi, nice web pages very interesting. When I was in school back in the late 50s early 60s all us kids had a top blazer pocket full of pens we would all do a swaps if some boys had what you did not pens changed hands all the time they could see what you had in your pocket. Wish I had them now!!!!!? Bob.
My husband remembers that swapping culture of the times very well. He says that unfortunately most of the pens he had were rubbish!
I think Gunther Wagner is a sub brand of Pelikan, Deborah
Gunther Wagner was the guy who took over the Pelikan business from the 1870s onward. The pelican was the emblem of his family and he made it the hallmark of the company.
https://www.pelikan-collectibles.com/en/Pelikan/Models/Revised-Piston-Fillers/400-Basis/index.html
detailed information on 500 here
Thank you kindly, John.