When Rigdon and Smith continued their work with Whitmer’s copy of NT1 in September, 1831, they began at Matt 26:1 where Whitmer ended his copying not realizing that they had already translated through verse 71 in June, 1831. There are therefore two revisions of Matt 26 with some differences in content.

A comparison of the two revisions is available at this link.

Some of the content additions to the KJ Bible are found in only one of the two revisions of Matt 26. 

Major content differences: 

“that they might put an end to his work” (Matt 26:4, June 1831 version)

“Why trouble you the woman? And from whence is this evil in your hearts?” (Matt 26:10, June 1831 version)

“and gave thanks, and blessed the cup” (Matt 26:27, June 1831 version)

“Jesus took bread, and brake it, and blessed it” (Matt 26:26, Sept 1831 version)

“which I gave a ransom for you” (Matt 26:26, Sept 1831 version)

In both versions of Matt 26, Jesus heals the severed ear of a servant. “And he put forth his hand and touched the servant’s ear, and it was  healed” (Matt 26:54, June, 1831 and Sep, 1831, but the two records include this event at different points in the narrative. This is an effort to reconcile the Gospel of Matthew with the Gospel of Luke, which reads: “And he touched his ear, and healed him”.