Hello John welcome to the forums. We need more information about both but.... Colnagos are well known and loved bikes. I would say this one looks maybe early to mid '70s but I am not expert. more info on the components and frame material would help the Colnago geeks.
Chesini, which I know little about, is a very nice but unknown brand name. Again some better pics and more info will help.
Are you buying or selling these? Do a search on these names in the forums and you'll get lots of information.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk