From what little I've been able to find about this rifle was that it was made in 1973. The following quote is from Colt an American Legend by R.L. Wilson pg 282.
"Colt-Sauer high-power rifles date from 1974; a product of J.P. Sauer & Sohn of West Germany, made to Colt specifications. The experts rate this bolt-action at the top level of mass-produced sporting rifles."
He does go on a little bit but he's mostly quoting Colt company brochures which paraphrase what he already wrote. Other than that I know nothing about these rifles. I hope this was some help.
Congrats on the new German Pony coming to live with you,