OK first metric bolts. Unless it is specialty, Lowes, Home Depot, Ace Hardware, Auto Zone, etc have metric hardware. Second, on the alternator, unfortunately dynamic testing is best. It is rare that a 1st gen a stator is toast. The usual culprit is the connector below the seat corrodes. The R/R is more prone to failure, and there are a lot of aftermarket ones out there that are good replacements. The R/R connector can also corrode and cause problems.
I would first have the battery checked with a good load tester, and if a replacement is in order then put a Deka AGM battery in. We will teach you how to fix the battery acid level sensor issue. It's an easy mod. Requires a 2000 ohm resistor being placed in series with the probe lead to the battery plus.
Getting back to the stator, you can check it with an ohmmeter, the value should be within 10% with any combination of 2 out of three white wires. Also, each lead to ground should read infinity. The dynamic test is to check the AC voltage between any combination of 2 white wires and they should be the same, and should increase AC voltage with increased RPM.
To test the R/R (Regulator/ Rectifier) check the voltage across the battery with a DC voltmeter. At idle you should see close to 13 volts, and more like 14 volts at higher RPM's. This test should be done after you confirm the stator is good, but if it fails before, then test the stator...
Keep up the work, we are here for support! There may even be a knowledgeable member close to you that can help in person. Trust us, a good running 1st gen is a treasure to be enjoyed!!!