Nut dishes...plate or 900...or 1000...or fake?

[mkad]

So I recently got these nut dishes, they're the typical average size, small...but they all have this marking that looks as though it either says A1000, or they say A.900c or it could be that they're not hallmarks at all, which is why I'm putting it here, because some of them are dirty, and look like there's brass peaking through. So either they're pure silver, or they're coin silver, or it's a misleading mark, or someone put a fake mark on them (but not the standard "925" or "sterling" which is unusual.)
So, pardon the rambling introduction, but does this look familiar to you?

[silverport]

Hello

The nut dishes are plated on brass metal.

The markings aren’t »Hallmarks« - please read here there fore a brief explanation: http://www.925-1000.com/silverglossary3.html

I “read” the markings as follow: AI 100G



AI = is extra strong Plate (A = is good strong Plate, B = is well plated, C = is lighter Plate, D = is lighter Plate; e.g. by Barker Brothers, Birmingham, around 1900).).

100G = 100 gauge plated thickness = 0.001” = 0.0254 mm = 25.4 µm

The nut dishes were maybe used very often; so by wear and tear the basic material is shown now.

Kind regards silverport

[mkad]

Once again I see how great this website is. Thank you for your response.