Identification of crest / cipher - initials mounted by crown with dragons

[casscass111]

I was wondering if anybody can help me identify what the initials and dragons on this chatelaine might mean and where it could be from. The initials appear to be 'MR' although there may be another initial in the middle, mounted by a crown and flanked by a pair of dragons. I can't find any marks, so I am unsure where it was made.