If any parcels or units of land merged under a valid local merger ordinance which was in effect prior to January 1, 1984, but for which a notice of merger had not been recorded before January 1, 1988, and one or more of the merged parcels or units of land is within one of the categories specified in paragraphs (1) to (5), inclusive, of subdivision (b) of Section 66451.30, the parcels or units of land shall be deemed not to have merged unless all of the following conditions exist:

If all the conditions described in subdivisions (a), (b), (c), and (d) above exist, only a parcel or unit

of land which does not conform to minimum parcel size shall remain merged with a contiguous parcel.