Is this MacBook charger counterfeit? I bought a supposedly original charger for my MacBookPro9,2 (A7A048) 2012 Macbook pro. It does feature the apple logo etched into the plastic, it also says


  Designed by Apple in California
  Assembled in China


On the one side. What seems strange to me is that on another side I find mention of


  DONGGUAN SOLUM ELECTRONICS CO.LTD


Which appears to be an electronics manufacturer, from brief web search. Is this simply the company assembling the thing for Apple or is it evidence of a fake? Unfortunately I don't have my broken original anymore to check.
It is not in itself evidence of a fake, no. It is common for Apple to have the name of the production facility written on the power supply. For example my 85W power supply has "Delta Electronics (Jiang Sui) Ltd." written on it in the same place.

An image search on Google for the 60W adapter also reveals that other power supplies have the same writing on it as yours.

However, it is not a 100% proof that your charger is original, as anyone could in principle write such texts on a charger. It would obviously be illegal however.