If your alignment is really bad and you are handy in the workshop and can turn a nut you may be interested in this clip.
This bloke is going to give it a crack.
Then take it for a spin. If it wanders pull out your spanners and give it , dunno yet, 1/2 a turn so it widens at the back of the axle. Repeat until it dosnt wander and your happy. Hell seek out some corners to double check.
I guess if it straight-lines too firmly bring it in 1/2 a turn or a 1/4 or two full dunno yet.
You should be able to feel it from handling and feedback in the bars when its right.
BYW A Poofteenth is exactly the the required measurement wider at the back than the front.
https://www.youtube.com/watch?v=Ho12zpOkAPA