Bramble / TIA:
I have one from a maker in Germany that I will install on an '88 action sporter carbine. It's new and in white.
I had this one brought for me from Germany a year ago.
Two sources that may help. NECG and the German Gun Collectors Assoc..
I like these because they can be dialed down below sight level for use with the open sights, then have the Rigby sytle sight for the over 100 -0150 range.

My need is a source of Mannlicher style german Claw Mounts. As with many german sporters, the rings and scopes are gone. The original owners, prior to the Allies confescating or destroying the sporting guns, took the only thing they were allowed to keep. The scope.

Mauser 88 Sporter fan.