What happened to Telephone Number One?
The following quotation is from The Meaning of Everything: The Story of The Oxford English Dictionary, by Simon Winchester. It's an excellent read. James Murray was the OED's most important editor and its chief architect. I can't yet confirm this story but most details seem consistent with Bell biographies. One note, Bell's original telephone consisted of two separate parts or pieces, the transmitter and the receiver. The story suggests a single instrument:
"Murray's already-mentioned childhood friendship with Alexander Graham Bell -- Bell had been best man at Murray's wedding to Ada -- continued to flourish when Murray lived in Oxford, with the consequence that after Bell had invented the first working telephone he presented it to Murray in gratitude for teaching about acoustics and electricity back in their younger Edinburgh days. Murray found the wood-and-bakelite arrangement somewhat uninspiring, and consigned it to the attic."
"In the 1980s the present occupant of 78 Banbury Road found himself at the AT&T museum in New Jersey, where the curator was bemoaning the fact that Telephone Number One had never been found. A search of the Oxford attic turned up nothing; but the elderly gentleman who had bought the house from Murray's widow was found, and reported that during the Second World War soldiers had been billeted at the house and, during one exceptionally frigid winter, had used all available bits of rubbish they could find in the attic as firewood."
"If this story is to be believed, the world's first telephone appears to have gone up in smoke, to keep a party of ice-cold infantrymen from freezing."