Royal crown derby cup and saucer

I bought this cup and saucer earlier today. I checked and triple checked for chips and cracks. I then noticed on the tram that the pattern on the saucer is smudged (at about 8 o clock). Not the end of the world but perfection imperfected. There is a score mark on the back so perhaps seconds. I'm not sure whether to try and clean it up or leave alone. Might end up looking like a pavement pizza.

I also noticed that the Roman numerals on the back aren't matching. This concerned me at first but it looks like it is quite normal for these not to be matching. I never even realised that they were date cyphers to be honest. The numerals don't seem to bear any logical relevance to the actual dates they relate to.

 

Well, I think that smudge mark is definitely a defect, so likely a second. If the patterns match then a set, not a marriage, but there are different versions of the imari pattern. However, maybe by that date, there is just one version -- dunno for sure.