Dear Miss Manners: I have formed the opinion (from multiple sources in literature, no doubt) that a manservant, particularly a butler or a chauffeur, is properly addressed by his surname, i.e. "Jeeves," "Hudson," "Cadmon," etc. etc., with no "Mr." preceding, and certainly no first name, by those he is serving, and "Mr. Jeeves/Hudson/Cadmon" by his colleagues.
However, I recently watched a BBC program on the restoration and reopening of a grand London hotel, which offers "Butler Service" to selected guests, and their butlers refer to each other and are referred to by their first names only. I suppose one could ask the butler/valet/chauffeur how he wishes to be addressed, but I would so like to get off on the right foot and would not like to appear overly familiar. Please advise me of the correct mode of address, as I would one day like to visit England and do not wish to offend.
Gentle Reader: In no country is it a good idea to model your manners on television programs or novels.
At best, you have to take into account what the behavior is intended to say about class and character, and at worst -- well, let us say that a knowledge of etiquette, historic or contemporary, is not necessarily brought to the writing of these works. Miss Manners has yet to see a period drama, British or American, in which supposedly well-bred people did not commit the social atrocity of eating and drinking with their gloves on.
But in this case, the mistake was yours, in thinking that time had stood still between the writing of those books and the recent television program. Therefore Miss Manners' rant was irrelevant, but she thanks you for letting her vent.
A butler was, as you have read, addressed by his surname alone, as was the chauffeur, although the lower servants were expected to preface this with Mr. The housekeeper and the cook had the title of Mrs. with their surnames, even if they had never been married. Footmen were addressed by their given names alone, but, with uncharacteristic choice, ladies' maids and parlor maids could be called by either their given or surnames alone. The nanny was called Nanny with either her surname or, in even older households, the surname of her employers.
However, as the years went by, the male upper servants began to be accorded a "Mr." with their surnames. As the decades went by, informality has pretty much swept away honorifics and surnames, except in the most traditional households.
If you do not want to inquire at the hotel desk, or of a private host, go with what you learned in those books. It is better to be thought quaint than cheeky.