Odd half moon writing desk Can anyone help me?

I purchased this mysterious desk from an auctioneer a few years ago, I BELIEVE I payed around $300 but I honestly can not recall. Little is known about the piece. I was told in all his years he had never came across a half moon writing desk, but then again he did call it a secretary too lol. Either way, its a little rough on the bottom and has a few scratches but is sturdy and I love it.There is a worn spot where a sticker or tag must have been but I can not find ANY other words or numbers.  I was just wondering if you could tell me the history or ANYTHING else?? Maybe a guess on when it was built? It has a leather piece for writing, and the larger drawers are dovetailed. I am GUESSING it is maybe mahoghany but would appreciate any opinions you may have. PLEASE HELP :)