I'm not sure if this monitor is already 'known' the be working, but I picked one up today in a second hand shop for £6 after checking quickly online that it seems to go to 'low rez' frequencies.
Got it home and some quick tests show it's pretty good. Medium res is a bit blocky and I couldn't gte a decent display even wieh playing with the on screen display options, but Low rez was pretty much perfect, after centering the image on screen. Hi rez also very crisp.
So, a few pics. I tried various PRGs that use the borders, all with good results. NEOChrome looks good, though may be slightly clipped at the bottom. Protracker also looks good (that pic is fuzzy as it's playing a MOD ) the demo is Cernit by DHS, a fullscreen demo, that also worked well. Fired up Gauntlet, looked good and some hires pics. Hires seems to have a top and bottom border but is still usable.
Since this is "...working with VGA" and what we see is color mode, lets assume this is via one of the Atari DIN -> VGA cable, or adaptor. There is several of them that allow color mode too. Besides I think this LCD does not have SCART interface at all.