Welcome o the forum; now STAY!!!!...lol
You may redo the solenoid IF it is the heavy contacts. Your curiosity may be piqued and you will want to disassemble the solenoid. With all the bolts removed from the cap end, gently pull the cap off and check the thick contacts. They may just need a little 'dressing' with a file or emery cloth. You may turn them 180. the wheel they contact with is most likely the source of pitting and poor contact. Either take the wheel off the little shaft and reverse it or clean it up as you did with the 'poles'.
Ensure that the sliding parts slide easily when you put things back. I bench test them and there is no doubt if they're working properly. You might have a reputable shop bench test your starter after you remove it from the car, but before you buy a replacement.
Then again, with all the work or R&R, perhaps a remanufactured starter is best. Note that I did NOT say rebuilt! The latter involves, typically, only replacing parts that need it; not ALL the wear parts.
Also, the stick shift car has a switch for the clutch that prevents starting w/o pressing the pedal. Mine failed and has been bypassed with a wire. there will be two; one is the cruise control disconnect. The starter safety switch has two wires: 1-yellow, 1-dk. green/white. Fun, isn't it, under the dash?
The tapping may a real or coincidental 'fix'.