I see many usages of the word FUSE in the diagrams, but nowhere do I see what ratings these fuses are supposed to be. For the 6-volt CT's and the 12-volt AT's, what fuse should I use in each? None of my manuals say, or I can't find them, and I can't trust the PO's at all on these bikes...
Thanks.

Edit: For instance, I have a CT-1C with a generic "10A" marked on it, and I have ridden it previously without trouble, and I have an AT-1C with a brand spankin' new fuse marked "362 8AG" at one end and "20A 32V" at the other.
I thought the AT's were 12 volt, not 32 volt...

Amps are amps when it comes to fuses. 

10 amp for 6v magneto models

20 amp for 12v electric start 125's.

Voltage rating just needs to be HIGHER than the voltage of the system.  For example, you would not want to run that 32 volt fuse on a 120v or 220v house circuit.  That may be unsafe.  But you could safely run a 10 amp 250v fuse in your CT as a 250v rating is higher than 6v.

Electricity and I have never mixed well. You make it simple, though. Thanks. What about the AG? What importance does that carry, as I know there are other markings.

Most important thing is amps and that it fits the fuse holder. And of course that volt rating is high enough but that's usually not a problem on these bikes.

"AG" is likely part of the type of fuse or a manufacturer code or something.  Might not mean anything.  If I remember correctly the Japanese used 5mm diameter fuses that were 15mm, 20mm, or 25mm long?  So they are usually called a "5mm x 15mm" for example.  MikesXS might or certainly Yamaha has them...  harder to find these days.

AG is a fuse type. Stands for "all glass" or "automotive glass" depending on who you ask. You want to use an AG or SFE type fuse. These are fast blow fuses. Automotive fuses are 32V. For AG fuses, there could be a number before or a letter after the AG. I.E. - 3AG or AGC. This denotes physical size.