On second thought........
I got off my lazy butt and found the "Original" schem here:
http://www.dreamtone.org/pdf/18watt_Schematic_08-28-03.pdf
It shows the tone knob just to the right of V1 with no resistor between the sweep and ground so, as ChrisL pointed out, it shouldn't hurt anything to leave the resistor out if you wish. It's funny, I didn't even notice the "R" after 100. My brain automatically read it as 100 ohms! I'm just starting to build my first amp (a 5E3), I'd better make sure I triple check against the layout too!