Narya and the Shire

[Tuor in Gondolin]

An interesting idea. Of course, Sauron had no need or
interest to learn about or find hobbits before Gollum
was tortured, and Saruman had access to the Shire via
spies and purchasing (tobacco) agents early on.

The three rings might indeed be pictured as a sort
of "cloaking agent". Perhaps periodic visits by Gandalf
would be enough to psychologically discourage persons
from visiting it, while allowing for travelers such as dwarves
to pass by. Recall Gloin's and Thorin's contempt for hobbits
in UT:

"What!" cried Gloin. "One of those simpletons down
in the Shire? What use on earth, or under it, could he
possibly be?"

(Thorin) This is not advice, it is foolery! I fail to see
what any Hobbit, good or bad, could do that would repay me
for a day's keep, even if he could be persuaded to start.