Vertical toolbar positioning

Have made button to toggle a vertical toolbar on and off, am trying to position it on the left hand side but it keeps appearing on the right side, am using the following which is not working properly

Did you not keep a backup of your old config before you wiped it to start again from scratch? If you have a backup then you can rename the file to .zip to look inside it and find how you did all these things in the past.

That is from backup, it's just starting from scratch has got me tweaking again. The 'left' was 'center' but 'left' not working.
Have it working now, rediscovered the help. Great stuff.