Thanks for your comments.
I'am not convinced to 100%, because it looks a bit dull in comparrison to the standart #61.
It wasn't mine....til yet! I saw this ebay "buy ot now" listing this afternoon and this #61 looked interesting to me and the rivet doesn't look that bad, too.
This one comes in a lot with 15 other superfasts / Superkings and it's round about 3€ per model, so I will be not that disappointed if this isn't the real deal. (there is a nice Sf Mercury Cougar which will make up for that

)
Thanks for mentioning christians site, Motorman! I had a look there, as one of my first thoughts were "Brazilian", too. The genuine red metallic blue shark looks definitely more gloss against mine example.
Christian lists a pre pro in non metallic red (hope my eyes are ok), that one looks brighter than mine. He also lists a brazilian issue in dull red, which looks brighter than mine, too and has an unpainted base, but I don't know if this is considerable.
My other thought was, that the one I found just got the priming for the blue paint, but the paint would be thinner than, or what would you say?
Maybe it's just a good Code 3 or a red shark will pair up with my blue shark.
Greetings,
Linus