This post is pretty boring, as I simply found some 6mm spacers sitting around and stuck them on the trailer in order to get the wheel centerline centered over the bearings (to improve loading and make them less likely to wear out prematurely). Also gets the wheels a bit more flush with the bed sides for cosmetic reasons.
Told you that was boring. So here's a couple shots of the Raider wheeling at Rausch Creek last weekend (sans trailer)