Blank face

Vils is with one leg in Tyrol. https://sammellust.ferdinandeum.at/page/objekte/1999b

So it was an optical illusion that the rib corners are wobbly and pinched. Like I wrote, in my eyes more from the Vils/Füssen region than Mittenwald.

I agree that this is a difficult one. Though a bob construction it doesn't look much Saxon/Bohemian - scroll reminds of the Vils region (though it can't be neither due to the construction), from the belly I thought even of old Netherlands, what's unprobable due to the scroll. So we need to wait till someone will come up with a better idea (and beware of calling it Tyrolean).

No, not by this photos. If a frog isn't split or broken after supposedly 100 years one can assume that it is of a good quality, at least. Speaking of experience, I found that the open pored ebony one can find with many of the older French frogs is relatively hard and stable, while the smooth and glossy deep black of Markneukirchen mass production is often broken. Not to mention the quality which looks even and homogenic, but starts to crumble when you're trying to carve it.

You’re still confusing “good quality” with “it’s optical pleasing me”, but ignoring that this can be properties being independent from each other. Ebony isn’t one particular species, but assembles different trees from different continents. Many German certificates for example are stating that a quality frog is made of Mauritius Ebenholz, while others are telling that such a claim can be hardly verified without an RNA analysis. Paul Childs has the right to tell a certain wood superior just because he is Paul Childs, and not anybody else.

Much of the appearance, and more at photos, depends of how the ebony was treated. This one looks as if it was polished with some chalk or lime, leaving whitish residue in the pores. You could treat it now with black shoe polish if you want to have a shiny deep black surface. As Martin said, with such categories you would miss nearly all of the great French 19th century makers, and the OP bow is most likely not a Markneukirchen in my eyes.

i would second this. By his more or less cryptic comments he seems to have some first hand ideas about the violin.

It wasn't the way that they could decide on their own how to work, but were employed by or depending of the wholesaler who paid them. So the work was executed in the way as it was profitable,

The problem with such documents, also old certificates without pictures, antique b/w photos etc. is that they neither prove that the instrument in question was actually a real Strad (giving performance violins a sort of admired but untrue attribution was very common) nor that it's indeed identical with what you've got now. Mr. Gerardi as well as Gordon McKay might have had owned many violins during their carreers.

There's no top hat with slots sidewards at the upper end visible to me (s. below). Open trench frogs were used everywhere, especially in Germany and France into the early 20th century, partially because some players still prefered them, but mostly to save time and costs. Same applies to "tropical" or simply Abeille wood (not clearly to tell by the dark photos). The frog and adjuster made me wonder a bit if it could be French, but the head gives it away as German IMO.

I would assume it's mid 19th century Markneukirchen made.

Good that the owner now is willing to contribute here. But I still don’t know if there’s now a written certificate by an actual expert, with a clear attribution by whom and when, which would settle the case and end the quest, or only interesting comments?

I didn’t examine so many of these, but surely there was a tendency during the between the wars period to outside construction in the better shops; this allowed more precision when producing larger numbers of clearly defined models, while building on the back leads almost always to differences between back and top plates. OTOH bob was still used in GDR times.

There seems to be some confusion. ”Italian style” can be any possible way of construction, depending of regional school and period. Assuming you have Cremonese construction in mind it means inside mould, usually with one piece lower rib, assymetrical corner blocks , C bout linings mortised in the corner blocks and nailed on necks. Outside mould construction usually has a divided lower rib and symmetrical corner blocks with mitred rib joints (typical example: 20th century Mirecourt work). That’s what Strad O is describing, with the idiosyncrasies of ribs inserted all the way into the blocks (not in the C bouts only) and what I pictured above. So there’s absolutely no contradiction between Roths using an outside mould and divided lower ribs.

It’s right that Czechoslovkia was founded in 1919 after the end of the Austrian-Hungarian monarchy. But I’m strongly assuming that these labels were inserted after many years of storage, what was common practice of the wholesalers, and the violins were made before WW1. Personally I never found a violin with a carved bar which I would stylistically put into the ongoing 20th century, no matter what the label says. This also applies to the OP violin.