mystery Rotol prop

Hi Guys can you help me I’m having to clear out bits from the garage for an impending move so need to move things on. I’m going to list on a certain auction site a Rotol prop I’ve had a number of years. I don’t want to use the ‘S’ word trouble is the root has rotted out and the only numbers I can find are on the yellow tip of the blade which looks like D1220 ?9v the question mark I can’t decipher the number