If you think it may be the wheel alignment have a look at this link it is how we used to do it back in the day. Possible to do it with one person but having a buddy do the measuring while you are doing the string makes it a lot easier. At least you may be able to rule out misaligned wheels as the issue.
Back in the 80s one of my Ducatis always seemed to go around left turns better than right so once when I was in Melbourne I took it to a frame straightener and he realigned the frame for me. He reckoned it was out by about 3/4 of an inch from the factory. I owned that bike from new, and in fact still have it, and so I knew it had never been dropped or abused. From memory he was out Ferntree Gully way, maybe someone else can step in here and advise if there is someone still out there doing this.
Hopes this helps or at least helps eliminate one issue it could be.