Once I tripped while moving a machine and rode a 1922 Brunswick York down half a flight of stairs. It survived the cabinet restoration.
Another time I "refinished" a 1930 Victrola 2-65 and the case didn't fit together right afterwards. It did not survive restoration.
Third, I took a 1909 Victor III out to do some DJing and the crank let go when it was wound up--there was a bang and we found the crank all bent up and cracked in the middle of the street, the escutcheon torn out of the side of the case. it was never found. Fortunately it has been repaired.
Fourth, tuning up a noisy governor in my 1914 VV-XIV I accidentally disengaged the governor, then stuck my hand into the gears to stop it when it took off at a couple hundred RPM.
Fifth, I accidentally emptied the mainspring barrel of my 1909 Edison Fireside A--directly into, um, the front of my trousers, and proceeded to walk funny for a day or two.
Sixth, I blew mineral spirits and graphite solution all over the basement when I was tuning up a Brunswick motor. I opened one of the springs to wash it in an old glass vase. That was dumb. There was flammable broken glass all over the place.
Seventh--you know Zip-Strip? I accidentally inhaled the fumes.
Eighth, I poured roach fras all over the floor when I was unpacking a "new" Amberola 30.
Ninth, I crammed nine or ten machines in a 12x10 room and proceeded to live in there with them.
Tenth, I spent $276 for a beat-up Victrola XIV (which I love using, so not all bad

)
Eleventh, I used some solvents to clean parts and got an incredible buzz/headache.
Twelfth, I found Victrola cranks can kick back if wound improperly.
Thirteenth, I blew up an Amberola 30 when a cylinder got stuck on it and I pulled the cylinder, thereby disengaging the governor and boom, sending the machine running at full speed.
Fourteenth, I sold my 1911 Edison Standard Model E. (Just kidding, you're a better restorer than I, Martin!)
Fifteenth, I bought not one but three 1940s cardboard portables.
Sixteenth, I made a homemade electric phonograph using a 1930s Grigsby-Grunow motor, a 2-tube amp from a Dynavox, a 1920s empty cabinet--and promptly blew it up when I turned it on. One of the new capacitors exploded like a gun-shot and fluff went flying everywhere. Fortunately my face was in the way, blocking it from getting on the carpet.
Someone else has got to have some horror stories.