I asked again the former owner of mug and flatware and he told me that the origin of the family Muchall-Viebrook was Scotland (perhaps only Muchall and Viebrook was added later because of marriage). The family moved to London and later to the north of Germany.
Thomas William Percival Muchall-Viebrook married El(l)ison Buchanan that is sure (perhaps around 1840, not sure and not known where). Some dates one can find in ancestry.com
Regards silverfan
