To my eye it looks familiar, but the two manufacturers I was thinking they may be are indeed definitely not it… I just looked them up again. Unfortunately the more I sit here and look at it, the less I can tell what it is!😵💫 Then I began to think it was a date letter/code…..heck…my eyes are definitely not what they used to be even a couple years ago.
Are there any other markings on the spoon, besides the “R” and “sterling” running down the handle? Do you have a picture of the pattern on the obverse side, that may help to identify the maker or at least narrow it down? I wish I could be more help right now, I love silver and have been at It in one way or another for the last 30+ years, especially spoons and trinkets of varying degrees….really enjoy the little stuff!
Good luck with the ID, the folks on this site really are quite knowledgeable and someone always seems to pull through!