I got one of those papers from my landlord. It's a beautiful document that I can, at best, use as toilet paper.

My landlord has no knowledge of any of the work that was done on the building, prior to him buying it. The previous managers did not keep meticulous records.

Is there lead paint on the property? Maybe. Maybe not. My landlord not knowing about it doesn't change anything in this equation.

If the property is older than the mid-1970s or so, it likely has lead paint. (It was banned in the US in 1978 but I don't know how widespread its use was in the years leading up to the ban.)

Related New Jersey had an odd requirement of repainting between tenants of apartments to try to remediate it. (Cynically kickbacks seem more likely given a proper stripping would fix it more permanently.)

Landlords need to paint every few years. The better ones are painting between tenants anyway. Paint is cheap, and covers a lot of ugly (most of it harmless ugly). Thus I doubt the state got much push back. Doing a proper lead mitigation would be expensive.