Malta letter opener 925 sterling silber

[silverfan]

Some days ago I got this letter opener from Malta. As items from Malta are presented rather rarely in this forum and this is my first Maltese piece I need some explanations. I only found one post about a letter opener from Malta saying that these marks were used later than 1920.
Does anybody know the maker GM and the year matching the letter B ?
Regards silverfan

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[silverfan]

Nobody an idea?
Regards silverfan