The marks from the left:
1. A rabota mark for Moscow (Greek delta) and 800 (fineness) with a cut end punched by the assay office on the request of the Soviet customs
2. A mark P in a circular shield. This mark (Cyrillic R) is most likely a "restoration/repair" mark and should be followed by a year mark but there is no year mark (?). I cannot understand why this "P" is punched?
3. The mark ММД and no idea of what is this abbreviation or what it means.
Now from the right (these marks are up side down)
1. VS in an oval frame...?
2. 800. This is the fineness mark
3. Looks like a "star/cogwheel"....?
4. Looks like a head, possibly with a helmet, looking left in a circular frame....?

Any ideas of its origin and meaning of the marks would be much appreciated