I got myself a s/h Westfield e4500 the other week, the rhythm/treble switch doesn't stay in the treble position anymore, where can I find a replacement switch, ideally upgraded if there is such a thing?? Also in the rhythm position it picks the pickup near the neck and treble is the one at the rear, I read somewhere it should be the other way around?? Also is it worth me upgrading the volume and tone pots as well? again if there is such a thing as an upgraded pot? cheers.