My understanding is that the two frames are missing from the end of reel 10, which is the transition from Luke jumping down from the carbon freeze platform (having just knocked Vader from there), and the doors opening on the cylindrical corridor he follows Vader down. So it would be right about the 2:53 mark here.

According to Darth Mallwalker in this post, it’s: 150,204 | 1:44:24 | Reel11 | Luke bounces on trampoline (end of Reel10)

I really appreciate the work you put into these.