Here scribe 2 of 𝓞 wrote down the singular work. Oliver Cowdery copied the singular into 𝓟, but the 1830 typesetter emended the singular to the plural works. The following subordinate clause has the plural works, which supports this emendation. In addition, scribe 2 of 𝓞 frequently omits the plural s (for a list, see 1 Nephi 13:23).
Usage elsewhere in the text supports the plural works. People are always judged by their works, not their work: there are 14 references to being “judged according to one’s works” and 5 to being “judged of one’s works”, including one in the previous verse:
Thus the 1830 typesetter’s emendation is probably correct.
Summary: Maintain the 1830 emendation of work to works in 1 Nephi 15:33 since the text otherwise refers to people being judged according to their works.