Starting woes '89 100Q

[Frank Stadmeyer <stadmef@connix.com>]

My wife informed me that she was having difficulty starting her '89 100Q.
Sure enough I went to check it expecting to find battery problems.  Instead
 it appears the starter is the culprit.   Sometimes the starter will engage
and spin the engine briefly before disengaging from the engine while the
starter continues to turn.  Try it again and it may work fine.  Another
attempt and it may just spin without engaging the engine.  

Anybody BTDT?  My guess is the bendix or the solenoid.  Are these available
separately?  Am I better off just getting a rebuilt and from where.  Who's
got the best prices.  How long can I expect to be able to get it started
before it craps out completely?  The thought of someone else driving my '91
200Q  while I work on the 100Q is less than appealing.

Thanks