Sure this whole concept makes little sense strictly from a numbers standpoint, but in this sport very little does! If someone enjoys fab work and is willing to put the time into learning how to make it right, then why not?
Jmdzuk keep the pictures coming! One of the things not discussed, unless I missed it, is narrowing the trailer track width like in the last picture. That will make it easier to maneuver and should reduce aerodynamic drag some, though the narrower track my hurt stability somewhat. I had considered converting my single axle bed over to something like that moon buggy trailer to tow my K5, though between having to source an 8k axle and all the fab work...well when a good deal on a used tandem car hauler came along that idea was shelved.
Whiterino, what did you tow the single axle trailer with? If in doubt I tend to go heavy on the tongue weight and it has apparently worked so far. Sounds like your setup was a bit finicky. Maybe a WDH would have helped. Iíve never used one, but guys that have tend to swear by them.