According to Pollak & Pollak; Cyrus Warren, 1804-1888, born in Hardwick, Ma (very close to where I grew up). Moved to Nashua in 1857, retired from plane making in 1875. Planes marked Nashua were actually made in Hudson. Planes with that mark are frequently found with over 500 known.
Looks like a sweet plane.
Jonathan
It looks like boxwood to me. I've had a number of C. Warren planes over the years and they were all top quality.They made fine tools. That's a gorgeous plane. Is the set of bits matched? If so the value is increased substantially.
Josh
Thanks guys. The irons look matched to me. The only markings on them are owner's marks though, j.proctor and J.P.