Dear Michal,
Thanks a whole lot for your prompt reply and the additional images!
I have indeed pondered over going to the museums in Poland, Czechia and Russia but my spine is really too bad at the moment.
So I think I would greatly benefit from a little help from you when your time allows you to. Just in case you care to see what interests me most about early firearms, please go to
http://www.vikingsword.com/vb/search.php?searchid=29633
and judge for yourself.
Have a nice weekend.
Best wishes,
Michael