I need a bridge rectifier for my vintage Dremel tool

@wylecote that is an old General Instrument rectifier. Now that company is owned by Vishay and dba General Semiconductor. The rectifier should be either a W01 or W02 Here is the datasheet for it W0XX Datasheet You can most likely find an equivalent at Mouser.com or Digikley.com (I prefer those since I deal with them a lot and their site makes it relatively simple to find equivalent components. If not their customer service department is really good as well). Of course you can purchase wherever you like. I do not get kickback for mentioning their service :-))