The 1967 Scofield KJV, other than changing most of the older words also has some alternate text, not KJV. This happens in Isaiah, I can't remember exactly the verses involved.
Perhaps one of the verses that you refer to in Isaiah is Isaiah 9:3.
There the 1967 Scofield has the same rendering as the 1911 Bible that Scofield was associated with ["increased the joy" instead of "not increased the joy"].
At this verse, the 1967 Scofield followed the reading indicated by the marginal note in the Masoretic Text as the KJV does in several other verses.
Concerning Isaiah 9:3, Ginsburg noted that the official Keri substitutes "to him" for "not," but he maintained that the difficulty was caused by the original Hebrew orthography being wrongly divided into two words (Introduction, p. 161). John Eadie observed that “the Masora gives fifteen instances where lo should be written so as to signify ’to him’--and not to signify ’not.’ Thus in Isaiah 9:3, in the clause ’thou hast not increased the joy,’ which contradicts the rest of the verse, ’they joy before Thee,’ the translators put the note ’to him’ into the margin--though it should have been in the text. In Exodus 21:8, ’not’ should be ’to himself’ as the Masora intimates, and this is accepted into the text without any remark” (English Bible, II, p. 209).
