Colleen, I don't know much about these folks, but I saw David and a brother Henry together in the Col. Co. baptism records for the 1700's. Henry married a Regina Krum (9 Nov 1783 Claverack) and had a large family named in his 1812 will, proved 1813; he owned a mill and property. A Hendrick Blunt is listed in the 8th Regiment of the Albany County Militia (Roberts, NY in the Revolution), no David or other Blunt listed. A Joseph Blunt married Luse Bronson 4 May 1785, also at Claverack.
The younger David was in Rensselaer Co. by 1850, see: http://www.rootsweb.ancestry.com/~nyrensse/