[Healeys] Problems with voltage regulator

[Maurice Maxwell]

Yesterday I backed my Healey out of the garage and drove it for about 10 min then home again.  While the engine was idling, it quit.  upon examination the armature arm on the cutout was stuck against the coil of the cutout.  Pulling the armature from the cutout gave a spark.  Turning the car cutoff to off also releases the armature.  Can this be repaired or not?  If it can be repaired, what needs to be done?  

How complicated is it to change to an alternator?  And is this a better route to follow?

Thanks in advance!

Max
1961 BT7