Message inside old book

Hey guys, had this book sitting on my shelf for a while. I bought it a few months back from an old bookshop because I found it interesting and only taken the time to try and read the message inside today. I can make out most of it, but I have no idea who the people are, what it’s in reference to, if it means anything. If anyone has any idea I would love any information at all. The book is from 1957 if this helps, it’s Medical Treatment by Maclean, associated with Guy’s hospital in England. The message, as far as I know, says:

“To: Major General W. J. ?????
D.M.S HQ M.E.L.F
From RD – 3 Oct 57
With compliments and thanks for his encouragement.”

It’s not a printed message, it’s written in this copy in particular.
I’m really curious about if there’s anything to this or it’s just a donated book from some old guy, lol.
Thanks 🙂