put it in the post:
The GT is 42 months, and Rev 11 has the two witnesses 1260 days ending at the same time as the 42 months end. That's when the 6th trump ends and the 7th trump sounds.
I think you are probably referring to Revelation 11:14
(the second woe of the sixth trumpet) as concluding the two witnesses' 1260 days. Correct ? Is that not the basis of your thought ?
Revelation11:14
The second woe is past;
and,
behold, the third woe cometh quickly.
But there is no mention of what the third woe is in the remainder of Revelation, verses 11:15-18.
Therefore, Revelation 11:14 is saying that John had already been shown what the second woe was (back in Revelation 9:13-21). And was about to the shown what the third woe would be. Note that before John was shown the second woe, Revelation 9:12 prefaces it with similar language as in Revelation 11:14. 12
One woe is past; and, behold, there come two woes more hereafter. Meaning John had just been shown what the first woe would be... and that were two more woes that he would be shown what they would be.
Revelation 12 is about that third woe and gives the relation of the two witnesses testimony of 1260 days being before that third woe takes place.
Revelation 12:6 - 1260 days of the two witnesses feeding the word of God to the woman (Israel), before the dragon is cast down to the earth. Then the war in the second heaven, and Satan and his angels cast down to earth in Revelation 12:7-9.
Then in Revelation 12:12 what the third woe is - stated to John,
who heard a loud voice in heaven...
10
And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
12 Therefore rejoice, ye heavens, and ye that dwell in them.
Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.