This is very interesting, indeed! Thank you
@Chrysophylax Dives and
@Androthelm
!
Trying to sort out my own thinking is likely to require more than a single post, so I will start out commenting on the introduction of the Shire into Middle-earth.
In this question, I find myself in something of a intermediate position – a ‘superposition’, I am tempted to say
Clearly the Shire did not exist in the first edition of
The Hobbit. Neither as a name or as a concept of a defined area in which the Hobbits lived – not even as a concept of a defined area at all.
This is, perhaps, nowhere as obvious as when the party of Dwarves, Wizard, and Hobbit are heading east, where subtle changes were introduced in later editions to indicate an area of Hobbit dwellings. In the first edition, however, we learn that at first,
There was a good deal of wide respectable country to pass through, inhabited by decent folk, men or hobbits or elves or what not, with good roads, an inn or two, and every now and then a dwarf, or a tinker, or a farmer ambling by on business.
Hobbiton would obviously have been a village of Hobbits, but that is all we get here. There is no “hobbit-lands” to pass through as in the later editions, and the inhabitants of the “wide respectable lands” are a motley group of races, men, hobbits, and even elves, and “what not”.
I do, however, think that the intention is also there to create, for
Hobbiton, specifically, an area that is reminiscent of England. This is not particularly strong in the first couple of chapters, and is generally only implied by Bilbo's wish for his tea. However, in the final chapter, the notice in black and red on the gate to Bag End is, for me as a foreigner, particularly telling, and, in my opinion, reveals that the produce of Hobbiton, if nothing else, is certainly grown in English soil. For me, this notice, even when reading the Danish translation as a child, came across as something English. As a child, I doubt that I distinguished between English and British, but I will nonetheless insist that “Messrs. Grubb, Grubb, and Burrowes” selling off “the effects of the late Bilbo Baggins Esquire” could not belong in Wales or Scotland.
If we combine this with the images that Tolkien made for (or before) the first UK edition in September 1937 (see particularly figures 1 through 10 in Hammond & Scull's brilliant The
Art of the Hobbit by J.R.R. Tolkien), we do, in my view, get a bit more local. On page 23 of his recent
The Worlds of J.R.R. Tolkien (also mentioned by
@Dorwiniondil above – I agree that this work is a very valuable contribution to this discussion) John Garth discusses the famous picture of “The Hill : Hobbiton-across-the Water” and how it was inspired by a picture of Faringdon Folly (in general, I think too little attention is often paid to Tolkien's own pictures as indications of how he envisioned scenery, and how his envisioning changed over time – but that is not related to this and will have to wait for another day

).
So, I believe that, in the first edition of
The Hobbit, we had the village of Hobbiton whose surroundings were intentionally reminiscent of the English West Midlands, onto which Tolkien had tacked certain other things, including stuff from his private folly and preoccupation, the Silmarillion legendarium, much like Niggle would use some odd and unfinished painting of some distant mountains to tack on to his tree and mostly paint over with leaves without worrying much about the mountains at all, while the Tree itself remained firmly rooted in the well-known soil.
I am not sure how this relates to Simon's ideas here. If I am right, we had, in
The Hobbit a vague and undefined area of land with deliberate reference or echo of the lands of which Tom Bombadil, in Simon's reading (which I am inclined to agree with), truly
was an aborigine, and from that concept Tolkien started developing this area into what we know today as the Shire – and here I would certainly agree with Simon that this development of the Shire and the wider area until Bree, should be seen as one process that brought forth the Shire, the Old Forest, Tom Bombadil, the Barrow Downs and Bree-land.