Oooh how exciting. Just got my first items back from the assay office and now I can (almost) see my makers mark on jewellery. Sorry, it's not a very good photo, the mark is teeny tiny, even viewed through my 10x eye loupe. That made me laugh because I made a point of choosing the London assay office because of their panther mark. It looks like a blob at this size though, or maybe a panda / teddy bear if you squint! The marks shown are - the sponsor's mark (my initials in triangles), the lion (traditional sterling silver symbol), 925 for sterling silver, the London panther head and the letter M which denotes the year 2011.
I don't think I chose the most economical way to do this, sending 4 items cost £31 including postage both ways (postage was about half of the cost), yikes. As if silver isn't expensive enough. I really wanted to test the process though (it was really fast 4 days all-in) and now I can display/sell these items as silver as opposed to precious white metal. But I think I may need to do chunky pieces in copper or silver plate and take commissions for silver versions in future!