I think the CPD G520P was released before the FW900 (tho I might be wrong)
The CPD-520P was released in 2002. I have a prototype released in 2001. The Sony GDM-C520 Artisan was also released in 2002 and I have prototype of this monitor also, which originally had a USB hub. The hub was not included in the production model.
The GDM-FW900 was released in 2000 and it was totally redesigned as it replaced the GDM-W900 and its bubbly screen. The Sony GDM-F520 was also released in 2000 and it replaced the GDM-F500R, which had a flat tube. Basically, it had the same tube (.22 aperture grille) but different chassis. The GDM-F500R was an small version of the GDM-FW900 chassis.
Sony used all the CRTs on all the production monitors until they ran out (some were kept for warranty replacements). The GDM-FW900's last production was January 2004. The GDM-F520's last production was December 2003, and the Sony GDM-C520's last production was September 2004 (very very few made), as most of them were released in July and August of 2004.
Hope this helps...