On the subject of artwork scans, I've been cleaning some Game & Watch backgrounds and foregrounds because why not, so here they are:
Donkey Kong Jr.
Mario's Cement Factory
Mickey & Donald

I've retained the full "slides" so that the hidden stuff is not lost, since the "default.lay" file can hide it, anyway. They're properly rotated and ready to use (I just don't know how to edit the layouts myself).

I'm not sure if MAME can do two overlapping layers of artwork yet so, just in case, I've also included the combined bottom screen of Mickey & Donald (in Photoshop, it was as easy as setting the top layer as "Multiply"). Also, you may notice that the top screen doesn't have round corners, this is because we seem to be currently missing "DM.53-S-F", which would be the layer that adds them. Any chances of getting it scanned, please?

I did a quick test by just cropping and replacing images while keeping the correct proportions and, to my surprise, it showed that there's currently a slight problem with the graphics size in this game:
LCD segments with current vectorized art
LCD segments with original scans

Looks like the car got accidentally shrunk somewhere in the way of vectorization and the LCD graphics were adjusted around the new car size, so they show up a little below their intended positions when the correct proportions are used.

Here's an image from the real machine, for reference: link

Also note that, while the background positions may indeed shift a little from one machine to the other, I combined the layers after positioning them at the same approximate centre point, which I guess may be giving the best possible results (the black frame even cuts the topmost "tall bricks" exactly in half so that they look just like regular ones): pic


Oh, and I also cleaned Thief in garden:
Folder with stuff

But it looks like I wasn't able to combine the clean layers in Photoshop properly in this case, seeing how the fence on the top-right is barely visible for some reason, as if the brown paint was under the yellow triangle.
[Linked Image from i.imgur.com]

...So I've also uploaded the PSD file in case that anyone wants to give it a try (perhaps the layer stacking should be handled by shaders and the images left as-is?).