I plan to have someone weld 4 sections of a layout using 6061 aluminum
which you can see
here.....https://www.flickr.com/photos/18223943@N06/14542109948/

This corner/section
https://www.flickr.com/photos/182239...n/photostream/
where the two pieces meet at the side, the corners touch. I cut the
other two corners for a flush cut.....
https://www.flickr.com/photos/182239...n/photostream/

Should I cut one side piece to make flush with the other for better
welding or will a good welder be able to fill that in for a secure job?

Thanks