Touch Lux 3 screen on Touch Lux 2 — almost

I've mentioned the Touch Lux 3 I bought a couple years ago on eBay that wouldn't keep a charge (the battery would drain in an hour or so even after I replaced the battery). So I found another (what was supposed to be) Touch Lux 3 with a broken screen on eBay recently (but it turned out to be a Touch Lux 2). In the archives of this forum I found that the Touch Lux 2 (which came with a Pearl screen) would work with the Touch Lux 3's E-Carta screen. So cool. I used the TL3's screen and front bezel, screwed on the TL2's board and used its battery (since the charge was about 97% as shipped and the battery leads were soldered to the board). I planned on using the TL2's back cover as well as it's in nicer shape than the TL3's.

It seemed to go well. Turned it on, light lit, it opened to an empty main screen, buttons worked... but the not the touch screen. After a little experimentation I figured which cables did what (main cable, light cable and touch cable). I reseated the cables several times, tried various resetting procedures, but no go. The touch screen was working on the TL3, but the screen connection for the TL3 appears to have a different chipset than the TL2's. It's also possible that the board from the TL2 was already damaged and the touch just doesn't work on that board. (No obvious damage.)

At any rate, not sure how it can be done, but would it be possible to install the TL3's microSD into the TL2's board? And would that make a difference? I'm just hoping that something in the TL3 firmware would get the touch layer on the screen to work.

Also, is there any way to upgrade the firmware without access to the TL3/TL2 Frankenstein's touch screen?

Sorry to ramble. Thanks for any info or tips.