I have a old Zinsco panel that the bussing is burnt, we did a service subpanel all the existing loads were moved to a new sqd panel. The only breakers that are in old zinsco is the main and one 100 amp feeding the new service subpanel. Inspecter told me I cant replace bussing from a old zinsco panel that I have that is perfectly fine. I have to buy one that is ul listed. My bussing that I want to use is ul listed. He said it’s code but could not give me a code reference. Is he right