New pictures.
This time in my back veranda, with daylight, before the sun hits the place.

.

Thank you, 'Nando,

Now it's clear even to me that the pitting of the pommel and blade is homogenuous. :)

Please bury my theories at Wounded Knee ... :rolleyes:

Best,
Michl

I thought I'd add two similar ones I ran into recently. This first one is listed on a German site as "Rapier, deutsch um 1600". The inscription is hard to read but according to the seller it's "MERTEN STOS ME FECIT", which sounds German. The quillons are slightly different, maybe a slightly wider blade, different grip wire, wider pommel. Otherwise identical.

This second one is listed as "ENGLISH DUELING RAPIER C.1625". No thrust plate on this one, but the pommel is more similar. Marked "THOMAS D AIELES".

I spotted another interesting speciment today that has Fleurs de Lys markings on the guard but is otherwise very similar to the example in the OP. Interesting, given that this group is typically associated with Germany, the Netherlands or sometimes the UK.