swash leveller is good cant ever hurt to have an extra tool
check out rdlohr's stuff.. its a bit overpriced.. but he makes these swash levellers that you dont have to remove the head to put those on, and they just slide on to your shaft. I havent personally used any.. but people like his stuff.. so see what you can find.
if its going left too much.. just pop the right swash ball and shorten it two turns.. see if just that might help..
sometimes, even if you eyeball and level your swash.. sometimes even with a swash leveller.. the CG might not be perfect center on all three axis ( and there is only so much you can control on that) .. and there might be a bit more weight on one side than the other. so just shortening one side will basically be like a mechanical trim that'll never change until you want to.. I prefer this rather than TX trim personally.. so if by chance you bump it one way.. or the other, you can mess it up one bit at a time. lol.. but thats personal opinion.. you can use tx trims to do that trimming too.. let us know what you do and what you find out.