Had the same problem. Replaced ignition switch but had same issue taking a golf club to the smaller Bosch solenoid usually does the trick. Sticky solenoids are an annoyance, but definitely much cheaper than replacing the entire starter.

 

It started today. Hadn't touched it since last night, when, just before taking her off the jack stands, gave her a couple of taps with a hammer on the starter motor. Was late for dinner and didn't try and start it. This afternoon, just after finishing the honey-do's, decided to just try it again. Turned right over.

Rather be lucky than good. I'll get a new starter motor

 

FWIW hitting the starter motor or the fuel pump for that matter with ant type of hard object,
could damage or crack the internal magnets.
be careful