Karchenko is probably the most accurate open cluster catalogue.
It gives M 67 at RA 08 51 18 dec +11 48.0
http://simbad.harvard.edu/simbad/sim...6A...438.1163K
http://adsabs.harvard.edu/cgi-bin/bi...6A...438.1163K
The main catalogue of open clusters is Dias.
It has the same coords for NGC 2682.
http://www.astro.iag.usp.br/~wilton/
http://www.astro.iag.usp.br/~wilton/clusters.txt
See also
http://www.univie.ac.at/webda/cgi-bi...gi?cluster=m67
The old NGC catalogue had poor coords for open clusters.