Hi. The clasp you bought is the original watchband for the 1967 or 1968 Omega Chronostop Geneve, which has a grey face and a red sweep stop watch hand. I own one, but no longer have the original band.
See the third watch in the first row at
www.old-omegas.com
for what the watch looks like. You can also see it in the second photo at
www.vintagewatch.ca
18.
I know this because I was given this watch with that watchband as a gift in 1968. The band is no longer made by Omega. What condition it the one you bought in? Are you selling it? Please advise. I am at [Email address suppressed for privacy].