Help with English (British) accent! {The Man Who Came to Dinner}

Recently, I was cast as Beverly Carlton from the comedy "The Man Who Came to Dinner" by Moss Hart and George Kaufman. Somewhat of a one-shot character (7 pages), Beverly is given the following sentence-description: "Very confident, very British, very Beverly Carlton." The way my director described him to me was as a very proud and snobbish character. On my first cold run through, I read with a Cockney accent, since I have that accent down-pat. Then she asked me to give him a "refined British accent"...that was quite a challenge, but I was quite literally the only person vaguely close. However, now that I've been cast, she's kinda just left me to hang and work it out on my own. However, we're also competing, so I don't want to be responsible for our possible defeat. There are one of a few things that I would like:

1) Can anyone direct me to a product (book, cd, what ever) that can TEACH me such an accent? It doesn't need to be from any specific area, but it just should be a "refined British accent."

2) Could I get a sample of someone with the mentioned accent speaking a few lines? If you could be arsed to record all of the lines (90-ish sentences total) that would EXCELLENT, but if not just a sample will do wonders:

"Don't tell me how you are, Sherry dear. I want none of the tiresome details. I have only a little time, so the conversation will be entirely about me, and I shall love it. Shall I tell you how I glittered through the South Seas like a silver scimitar, or would you rather hear how I frolicked through Zambesia, raping the Major-General's daughter and finishing a three-act play at the same time? [To Maggie] Magpie dear, you are the moonflower of my middle age, and I love you very much. Say something tender to me."

3) Two pages on, Beverly starts speaking with an accent of his own: [He goes immediately into an impersonation of His Lordship. Very British, very full of teeth, stuttering.] "Not v-v-very good shooting today, blast it. Only s-s-six partidges, f-f-four grouse, and the D-D-Duke of Sutherland. Haw, haw." How would I go about doing an accent within an accent?

If you could help me with ANY of the above, that would be GREATLY welcomed! Thanks!