Hi Jurgen,
Thanks for the tips, I am actually dutch and will check this Jemako stuff out, maybe can get it cheaper.
Even though True bleu is made for carbon steel (like Super blue) is works just fine, which makes wonder what the actual differences are and why it would not be suitable for Brass.
I stumbled upon a post from Danny, explaining how he does the bluing, aslo using balistol and other products:
https://www.stoomwereld.be/brass-steel-blue-patination/I guess I just need to go buy the stuff and see for myself next restoration.
I wonder what recipes Josef,Jean,Ernst,Georges and Ignaz were using, maybe these are lost secrets.
Regards,
Maurice.