I've just installed a pair of Classic Amplification pickups into my 4003... VAST improvement on the tone. It's a cliché but it's like taking a blanket off the speakers.
I've now got all the clank I could ever want - with everything on full in vintage mode it sounds like Jon Camp, real presence and growl. I am very pleased.
The only downside is a slightly lower volume on the E, thanks to the non-adjustable poles, but I'm hoping a tweak of the action and pickup height will remedy this.