Let me try and make this as clear as I can. I wish I could show you in person because that's easier.
There are two ways to do this. You need at least 2 poles, but you can also do it with 3 poles.
As you mentioned, to just switch between two caps, you'd put one cap between 1 and 4, and the other cap between 3 and 6, and lugs 2 and 5 would connect to the spots on the board. Now, if you wanted to add to that setup, and change nothing but including an LED, you would need to add another pole. This last pole, numbered 7, 8, 9 from top to bottom, would have a ground connection on 8, and you can either have one LED for one side or an LED for both sides. Whichever cap you want to have the LED light up for, that's the side you connect the negative end of the LED.
If you want to just use a 2PDT switch, you would have to adjust the way you do the caps. You would leave one pole to the LED, and it would be the same as above, with the GND on lug 5, and the LED on either 4 or 6 depending on which cap you want to light up. But the caps would not attach to two lugs. Instead, you would go from one pad on the PCB to the middle lug (2), then each cap would attach one leg to the switch (lugs 1 and 3, one for each cap), then the other lead of the caps would BOTH attach to the other pad on the PCB. In effect, it's the same thing as above, just using a DPDT switch instead of a 3PDT switch.
Jacob
There are two ways to do this. You need at least 2 poles, but you can also do it with 3 poles.
As you mentioned, to just switch between two caps, you'd put one cap between 1 and 4, and the other cap between 3 and 6, and lugs 2 and 5 would connect to the spots on the board. Now, if you wanted to add to that setup, and change nothing but including an LED, you would need to add another pole. This last pole, numbered 7, 8, 9 from top to bottom, would have a ground connection on 8, and you can either have one LED for one side or an LED for both sides. Whichever cap you want to have the LED light up for, that's the side you connect the negative end of the LED.
If you want to just use a 2PDT switch, you would have to adjust the way you do the caps. You would leave one pole to the LED, and it would be the same as above, with the GND on lug 5, and the LED on either 4 or 6 depending on which cap you want to light up. But the caps would not attach to two lugs. Instead, you would go from one pad on the PCB to the middle lug (2), then each cap would attach one leg to the switch (lugs 1 and 3, one for each cap), then the other lead of the caps would BOTH attach to the other pad on the PCB. In effect, it's the same thing as above, just using a DPDT switch instead of a 3PDT switch.
Jacob