Sony ended CRT computer monitor production in 2004. (Except Artisan, which got another year I think.)
No F520 rebrands I know of.
Fear was in the air back then that Sony would cease production...then Sony stopped accepting orders from their website...then the announcement was made...and queue in over a decade and counting of display frustration...
http://forums.pcper.com/showthread.php?260932-SONY-GDM-F520-(21-quot-22-CRT)-monitor-for-LCD-trade
As far as I know, Lacie and Sun both use rebadged Sony GDM F520s as their top of the line CAD monitors.
Anyone know which ones were these?