What determines sale location? (sales/use taxes)

I'm sure the experienced buyers & sellers around here have run into this
before....

One prospective plane I'm looking at is for sale in Connecticut (currently
based there). The current ownership is in a Delaware LLC (of a sole
proprietor, who is flying/basing the plane out of CT). Connecticut has 6%
sales tax that apparently applies to even "casual and isolated sales" of
aircraft; Delaware has no sales tax. I'll leave it as an exercise for the
reader to decide which I find more appealing....

So, "where" does this airplane sale take place? Is it wherever the keys get
handed to me? Is it DE, since that's where the owning entity exists? CT,
since that's where the plane's based? Whatever we write in a purchase
agreement?

Separate but related question: Colorado is where I live--BUT, I'm here on
active duty military orders, and my official state of residence is Oregon.
It says so in my military records, any state income tax purposes are with
OR, my motor vehicles are registered in OR, I have an OR driver license, I
vote in OR. I've read AOPA's discussion about Soldiers' and Sailors' Relief
Act *not* applying to aircraft based in the state of assignment, but I
wonder if that's the whole story? Does anyone know more details on that,
ways to avoid paying CO's 2.9% "use" tax (what a crock!), etc? 2.9% sure
beats 6%, but it's not nearly as good as the 0% that OR would want. Is
there some way to register my plane in OR and avoid CO's sticky fingers? I
haven't paid sales taxes on any sort of big-ticket item before, except for
the time I was foolish enough to register a car in Florida--this is killing
me!!

Any magic bullets?? I seem to recall the discussion here a couple of weeks
ago concluded that there's no advantage to an LLC ownership construct for a
single person & personal use (i.e., me)--would that help me here at all?

As usual, thanks for any help or advice!
--
Doug
"Where am I to go/Now that I've gone too far?" -- Golden Earring, "Twilight
Zone"
(my email is spam-proofed; read the address and make the appropriate change
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