Every deed hereafter given by the City of Mount Vernon pursuant
to Article 11, Titles 2 and 3, of the Real Property Tax Law of the
State of New York shall be presumptive evidence that the action and
all proceedings taken for the foreclosure of a tax lien by an action
in rem and all proceedings prior thereto from and including the assessment
of the lands affected and all notices required by law were regular
and in accordance with all provisions of law relating thereto. Such
deed shall be conclusive after two years from the date of the record
of such deed unless at the time of the taking effect of this article
the two-year period since the record of the deed has expired or less
than six months of such period of two years remains unexpired, in
which case the presumption shall become conclusive six months after
this article takes effect. No action to set aside such deed shall
be maintained unless the action is commenced and a note of pendency
of the action is filed in the office of the proper County Clerk prior
to the time that the presumption becomes conclusive as aforesaid.
This article shall take effect 45 days after its adoption.