Hi Kevin,
I'm not a fan of hand launching either, so I made a dolly for my Magnum around a year ago.
Initially I had a fixed tailwheel similar to yours but found that it wouldn't track straight down the rwy. So I ended up making the tailwheel steerable by installing a flight pack to the dolly (Rx, Battery and servo). It works perfectly........[8D]...........All I need to do now is learn how to land on it...........
Good luck with your dolly, one thing I do know is you'll never go back to hand launching once is sorted.
Cheers
Ken