I carefully looked once again at that last mark and can confirm that it does indeed read "MV" and not "NV".
Now, I have just talked to my 87-year old father over the phone to get more information on this spoon (including dates) and he related to me information that I don't recall having heard before and that I wasn't previously aware of.
First of all, he told me that my great great grandfather was born in 1854. So if we extrapolate from that date, and assume that he was, maybe, about 20-years old or so when he was a King's Guard, that would put the date somewhere around 1874.
Furthermore, he relates that in the 1930's, his father also told him that my great great grandfather's aunt was in charge of, or head of, the Danish Mint and, as such, was the only person besides someone from the royal family who was allowed to use the royal mark on her own silverware. I wasn't aware of this previously, or had forgotten about it if I had ever been told about this earlier. Unfortunately, neither my father nor I have any other information about her.
So now the possibility excists that perhaps this spoon came from her own personal collection, or maybe she pinched this spoon from the royal family's collection as that this would correspond to your interesting remarks, MLF, that perhaps the "HR" stood for "Hussar Regiment", which does make sense. Unfortunately, we don't know the name of my great great grandfather's aunt and so cannot attribute the "HR" to her personal initials.
As happens so often in circumstances such as this, family history can be so easily lost over the years, and this is one such instance.
Any further comments would be greatly appreciated. And does the "MV", which has been related here to be in the position of the maker's mark, mean anything to anybody?