does this site help?

http://registry.faa.gov/aircraftinqu...um_inquiry.asp

Also the 'R' in your question may not be accurate per http://www.landings.com/evird.acgi$p...*prefix_c.html

United States of America (USA)
N [x]1 - [x]99999, [x]1A - [x]9999Z, [x]1AA - [x]999ZZ
(letters "I" and "O" are not used, so they can't be confused
with the digits "1" and "0"), (x = category = C/L/R/S/X),
the '-' (dash) as separator is normally not used, but can be
sometimes seen applied before or after the category prefix,
which itself was normally displayed up to the mid-1950s,
while today only (some) oldtimer (are allowed to) show such
a prefix, the categories are: C = Commercial
L = Limited
R = Restricted
S = Standard (?)
X = eXperimental

There is a site that lists where planes exist (boneyards) and their N Numbers but I could not find it.

I think the FAA site is what you may be looking for.

Found simply by 5 minutes using Google.