Ok.
Note that I am not a 3d modeller so I don't know how to properly render these. I just took a bunch of editor screenshots of relatively low quality, but it should show you the proportions.
Breda 20mm
Flak 38
Flak 38 on Sonderanhänger trailer
Flak 38 Vierling
M33
M51
@Wiking: Thanks! I wasn't around back then though, I only became a dev last year for this Omaha Beach map:
https://www.youtube.com/watch?v=9K7n7x08fwg
Sometimes I wish BF2 mapping was as simple as WinSPWW2 mapping...