In the US, tax and land parcel ownership information is a matter of public record. I'm posting this for only that exact reason i.e. anyone can look this up. Mark purchased 36 Bank St. from Lionel Chute, who seems to be a relatively unknown actor, in November of 1982 for $319K. He satisfied the mortgage in full in November of 1985. (Remember, he toured the NYC area the month prior.) He then sold it for an undisclosed amount in December of 1993. Now, the deed doesn't specifically state Mark's name of course. His trust at the time was a company named "Charisong Inc.", whose sole employees were...Mark & Lourdes Knopfler.
Charisong Inc. was dissolved in 1994.