I'd press Circuit City to connect the dots for you and give you useable
estimate paperwork. For one thing, I can't believe that the serial
number was not recorded by their contractor as protection against
someone alledgedly (or actually!) getting the wrong laptop back. If so,
they should be able to fax Circuit City a more complete estimate; after
all, they should want to keep THEM happy. If not, it should still be
resolvable. Combined with your existing estimate, laptop, and firm,
on-site logic (harder to ignore than a phone call), you should be able
to have them fix you up with complete paperwork at the customer service
counter. Make it clear that you are not asking them for fiction-- just
completeness! Even if this is a bit of a hassle, it should(?) take less
time than starting over with other alternatives.

Of course, my suggestion is not definitive; if someone has
Minneapolis-specific (or not) info that might help, jump in! Good
luck... and let the group know how it went.