I have seen images of many Titanic release print film cell strips that were being sold loose on ebay and elsewhere. What I noticed is that when I extract the full height of those cells and crop out the rounded edges at the sides, I get an aspect ratio of about 2.20:1 (around that) not 2.39:1. The 2.39:1 is achieved by further cropping the extra height.
The anamorphic “squeeze” is 2:1. Here’s a cell off the internet:
And here it is cropped and resized:
As you can see it is 2.35:1, not 2.2:1. It’s not possible to reconstruct the 70mm version from 35mm, you’ll need to get a 70mm print for us to scan for that. When cropped it comes to 2.39:1 as so:
If you crop the rounded edges out, without cropping the top & bottom, you’ll get around 2.20:1. I was talking about preserving the full height. It can be done. In the 2.39:1, you have cropped the top & bottom out, as visible from the lines.