On closer inspection I see that what broke is the actual glass, not the glue between the glass and the metal base of the mirror assembly.
I can see the glue or a black colour near the metal and then a lump of glass with the characteristic ondulating round shape.
In this situation, I think it is best to not remove the glass from the base of the mirror and glue glass to glass.
In this case, is it better to get a glue for glass like
http://www.screwfix.com/app/sfd/sea/...pi=1&cn=1&cd=1
or is my best bet still the Loctite Rear View Mirror Bonder?
http://www.diytools.co.uk/diy/Main/P...roductID=11784
Thanks,
Antonio