Square D split bus modification?

Square D split bus panel with service disconnects at top of panel. What I’m inquiring about is the top left breaker/lower disconnect wires and how the wires appear to just be tucked behing the lower bus bars (visible on left side). This seems unorthodox to me. Usually they’re lugged. Is there something behind that I’m missing or can anyone provide any helpful info/recommendations? Thanks in advance.

BTW, there were numerous defective conditions present at this panel and throughout the residence that I’m aware of - only inquiring about the above :wink:

IMG.jpg

IMG.jpg

IMG.jpg

On some split buss panels I’ve encountered, those conductors are factory spot welded or soldered to the front or back of the “lighting” buss. This may be one of them.

Now that you mention it, I do recall a few in the past that were spot welded on the front bus. Thanks for the reply.