Old aluminum cookware - or is it really steel

I've been considering getting my parents some new pots. I hear aluminum and alzheimer has a link and since they are pretty old now... it's probably a toss up on whether or not to replace their pots and pans. Here comes the dilemma... Is their pots the non magnetic stainless steel or is it aluminum. I was relatively assured it was steel but my parents are pretty clueless in many things so why would this be different.

Unfortunately there isn't any noticable markings on the cookware and they basically assured me they have had it for years and love it even though the outside pot is stainned quite a bit which leads me to believe it is not stainless steel. However after 20 years it's held quite well so maybe it's just brown stains. I simply cannot tell. Can anyone help?

I am glad I am using cast iron but my parents are too hold to handle most of them properly.

#update. Apparently they are stainless steel with the 18/10 non-magnetic stainless steel. Mostly tools of the trade brand from macy's and one Revere. This is the second time in the recent months a quick search off the internet has caused unnecessary confusion.