You said that the engine turned over, but didn't catch when you tried to 
start it. If this happened the sarter and soleniod should be fine.  If 
they weren't the engine shouldn't turn over.  My guess would be water in 
the gas.  This happened to me.  I would be driving along and the motor 
would lose power, or cut out and catch again.  If it died it wouldn't 
start until a few hrs later when the water settled out of the line.  Look 
for droplets in the fuel filter (if its clear) or through some dry gas in 
the tank overnight or while your're at work and see what happens.  That's 
what cured it for my.  The other guess I would have is rust.  On my 
beetle the fuel tank was so rusty it clogged the strainer in the tank and 
killed the engine.  It would sart the next moring after the rust had 
fallen of the strainer.  I found this out when I disconnected the fuel 
line from the engine and noticed nothing coming out before I plugged it.  
I hope this helps.
Erik
71 Westy