Is there a website that tracks historical stock prices that DOES NOT
historically adjust for mergers/acquisitions?  I'm looking for a site
that can give me ORIGINAL stock quotes for companies that may no
longer exist or have been acquired. (Typically, we need to go to old
Wall Street Journals at the library and look up information on
microfilm.)  For example, KeyCorp [KEY] acquired Society National Bank
[SCY] back in the 90s. I can no longer find original SCY stock prices
electronically because technically the ticker SCY does not exist
anymore on the stock market. This information is EXTREMELY helpful for
people trying to calculate their cost basis when preparing their
taxes.  If there isn't a site, this would be a great add on business
for Google! (I work for a public company and receive these questions
frequently.)

Doesn't Yahoo Finance provide historical stock prices which are not
adjusted for stock splits, dividends, and the like?

No... (unfortunately). Everything is adjusted.   I'm sure there must
be a company out there that provides the info for a fee. I'd be
willing to pay.  Thanks though.