Thanks for these schematics, they've been very useful. I've assembled the alternate tone version with the stock parts you describe in the first post. I skipped using the ground jumpers to the third pin on the pots - just out of sheer laziness, really. When I tested the wiring by plugging it in to an amp and tapping on the pickups, everything seemed fine. Will I live to regret not installing the jumpers?
I'm quite not sure what 'ground jumpers' you mean. Did you use the 2nd diagram down in the first post? Connecting the third lug of all the volume pots(and the case) to ground is vital for the correct operation of the volume controls as the volume pots operate as potential dividers. Without the ground link they will just act like variable resistors. You'll get the signal through as normal with all the volumes turned up, but you won't be able to turn the volumes down to zero, and the volumes will get weaker but will never drop to zero. You are effectively adding up to 500k ohm resistance in the signal line with the volume pot wired like that , but it's not the same as connecting the signal to ground. Only the tone pot doesn't have its 3rd leg connected to ground as that needs to operate as a variable resistance.
If you've connected the ground wires to the 3rd leg of the volume pots, but haven't connected them to the pot casing, then the casing will not act as a shield and electrical noise can get in. The higher the circuit resistance, the more noise tends to get picked up. You want as much shielding as you can get on a guitar, especially a hollow bodied one where you can't shield the pickup and control cavities.
So all the wiring in that diagram really is required.
Thanks for the info! Yes, I'm talking about the 2nd diagram. Based on what I've learned from your post, I will fix my wiring to be exactly like the schematic.