OK, one last meager attempt to help clarify a point or two prior to my annual departure for Europe.
Language is one of my things, so lets focus on that.
My disdain for the term "Shimmel" has been previously aired. So, in short, it is a recently popularized term that is essentially a form of supercilious ostentation of erudite vacuity. That's it, put in simple semantic terms. Or, if you prefer, a recently coined word, with lousy pedigree that is used by many but understood by few, and more of a nuisance and source of confusion than it is worth. Are you talking about simple mountain guns? Barn guns? Define the necessary characteristics...no plate, simple guard, no glitterati? OK, we get it, with or without the term "Shimmel."
See how a living, vibrant language works? The boys in the hood will coin a new term for a fresh product overnight. The country boys coin a new term for a basic gun. No problem. Jimc2 is right. Go to Chuck's place where he has about 15 real ones on the wall and heft them. They are not the holy grail, but are an integral part of our firearms history. as are the glamor guns. At least you can rest assured that these are what they appear to be.
Now with Allamengal, or however you wish to spell it. Youngsters, please know that this word was never, in my experience, used to refer to a region, or to a "school of gunsmiths" or anything else until about 1995 or so. It was coined, or at least popularized, by one capable friend who is personally interested in guns from the lower mountain region north or I78 between Reading and Allentown. The Hess shop would, apparently, be the epicenter, and the rest of the builders you may not have heard of. They are not the big names. Point is, this long rifle commentator is still alive, neither canonized by the Pope of Rome, or anybody else. He's human, too; he spread the term; he's still writing and promoting his interest area, which is fine. But don't get too wigged out trying to define the area, as it appears on no current maps and can only be described subjectively by the minds that find it useful. A few see it as a school, recently revealed; others do not, but view it as more of a sub-school of eastern PA makers who shares some stylistic motifs and details. Regardless, any lines of demarcation are recently created and arbitrary.
Hope this helps. Some have books for sale that will speak of the region with profound authority. The region was always there, but the term was not popularly used to refer to it. Again, am I being negative? No. It is simply another example of a language that is not dead. If a term works, it sticks. The verdict is still out on this one.
As for "experts," you mention Tom Ames. He told me once that "Allamengal" meant "all wants" which, according to him, meant that when the Dutchies arrived in Heidelberg, Weisenberg, and contiguous townships, that their prayers were answered. Down the lane, another "expert" told me that it meant something entirely different...rocky soil, or some such. Take your pick. It's all opinion that was being formulated at that time. I was born and raised here, PA German on both sides, and some of my ancestors came off the good ship Harle prior to the Revolution. I read a lot of non fiction. I never heard of it until a few collectors with a personal agenda started using it. End of my ability to clarify. I don't know everything, and am always willing to learn. Perhaps the term pops up in some obscure text from antiquity and has been resurrected.
From what the old timers have told me, none of this school stuff was kicked about until AD...after Dillin. Then the latter day saints...Kindig and Kauffman wrote it into the canon for all ages. Maybe others will find additional details about other schools and other offshoots may emerge.