Hi Steppsch,
I would be nice if anybody have experiences with it and can say something about the quality.
Leica occasionally runs Digiscoping workshops, for example at last year's Hansebird fair, where I took part in one. I don't think there's any reason to assume it wouldn't work with an older type Leica.
The Leica representative herself used a phone adapter creatively manufactured from a eyepiece cap with a hole drilled in the centre, to which she attached her smartphone with a "sticky" strip normally used to mount navigation devices on car dashboards. A variant she had used previously was using a plastic cup ("Joghurtbecher" style) modified in the same way, wrapped in black tape to keep the light out.
However, smartphone adapters for Leica scopes were available at the Kowa booth
Kowa makes smartphone adapters for their own range of scopes, and you can buy one of these, plus a third-party manufacturer's Leica-compatible eyepiece adapter to replace the Kowa-compatible one, and there you go.
My girlfriend bought one set of these for her Leica Televid 65, but didn't get around to use it much before she had to replace her malfunctioning phone, and the new one didn't fit the adapter, naturally :-(
I'm not sure how well the Leica scopes are suited for mounting cameras. At their workshop, they naturally used a Leica camera, but of course the option to use other brands would be nice. It might have been mentioned after I had to leave the workshop for another event on the Hansebird ...
Regards,
Henning