I'd suggest adding "horseless carriage" to the search -- many of the
people interested in cars that old use that terminology.  I'm hardly
any sort of expert on the make or the era, but I've always had the
impression that the REO was a nice item from the early days of the
mass-market car, not a high-performance or luxury model.

A quick look at
http://www.kruseinternational.com/results/return.asp?RESULTS=1&MAKE=REO&MODEL=&I
MGGO.x=20&IMGGO.y=5
suggests that he isn't  going to retire the mortgage or send the kids
to Yale on it; but still, there might be a nice little piece of cash in
his future if he can connect with the right buyer.

I'd further speculate that much depends on condition and completeness
-- this probably isn't a car backed by a vast aftermarket of New Old
Stock or reproduction parts.  My advice (which may seem painfully
obvious but is worth mentioning anyway) is that he shouldn't throw away
anything that might  belong on or with that car, even if it seems
broken or hopelessly rusted.  Amazing what can be repaired or at least
used as an example of how to fabricate a new one, if the machine is old
or unusual enough.

Also, he shouldn't try to fix anything unless he chooses to keep the
car and take it on as his own project all the way through.  Aside from
the risk of ruining something, or repairing it in a way that an
correctness-minded  collector would just have to undo, the act of
taking things apart is instructive and useful to the person who
eventually has to put it back together.

Here are some further links that might prove helpful:
http://www.hcca.org/
http://www.kettering.edu/news/archivedDetail.asp?storynum=108
http://info.detnews.com/joyrides/story/index.cfm?id=116

Best of luck,
--Joe