Imho this ring can be assumed, what we can at least see from the pics to be an original one but unfortunately was "cleaned" in a VERY unprofessional way. In pic rsz_5f4edf7e-3411-4d17-879c-b57a33b9e55a.jpg you can see that obviously even a grinding machine was also used for "cleaning". Unprofessional "cleaning" does happen to ground dug rings very often and this way they are ruined forever. Their appearance after "cleaning" let doubt about their originality.
Due to the extensive unprofessional cleaning the outer structure of the ring (which normally can be seen even at well worn rings!) is nearly totall gone. The "cleaning" also did remarkable harm to the inspriction.
Only very experienced (with ground dug items) collectors and experts should professionally clean such a ring. Even more as the material is soft (but durable under the layers of dirt and outside patination).
Once I did mention this in another forum and was criticized because the there shown ring would be so nice. All ignored the very bad scratches and much moore which has happened to the ring.
I personally would not buy such a devastated ring, whoever did own it. It is simply forever ruined history.
If this ring would have been professionally cleaned it would have been a beauty.
Regards,