Ornate Desk Clock with .925 London import marks?

[ScrapPappi]

Hi everyone, I'm somewhat new to collecting and having some trouble identifying the hallmarks for the piece below. I enjoy trying to put the historical information back with the piece so this is the best part of collecting for me, but this one really has me stumped. From my limited knowlege, it seems to have a london assay mark (Constellation Leo), but I don't understand why some of the assay marks are inverted and other are not?? Is there some difference between the two? Not knowing the difference has me unsure of the date mark. Also, the makers mark is also unknown to me.. looks like an interlocking JCM or CJM but haven't found a match through my searches so far. Any help is appreciated.. Thnanks!

[silvermakersmarks]

All 3 elements of the hallmark are the right way up so I'm not sure what you mean when you say that parts are inverted. The date letter Q is 1990. From the shape of the sponsor's mark I guess that it might be SJR - S J Rose & Son. I can't help with the monogram which might, or might not, be the original maker's mark.

[ScrapPappi]

Thanks for your help. Just curious about the London assay hallmark, most of the hallmarks on the web show it inverted - but on the clock it's not. Just looking to understand the difference between the two. Many thanks!

[larkfield]

Hi
I believe the London import mark was turned upside down from 1975, so that shown for 1990 on the clock is correct way up