How to select preferred graphics mode when booting OS X from Grub2

Well, it's not actually OS X (as in Leopard or Snow Leopard) but the PC patched version which can run on a PC
As I've already posted I'm using Kalyway 10.5.2. on a Dell Dimension 9200 with C2D 2.13 GHz, 4GB RAM and nVidia G210 video card.
I mentioned in the post that while booting the OS using it's own bootloader can easily provide the required screen resolution (1680x1050), booting through Grub2 does not apparently because Grub ignores the com.apple.Boot.plist file.
Nevertheless, I've now come across two means to get the desired resolution in a Grub2 boot.
The first just requires you to add the line

gfxpayload 1680x1050x32

after the line

insmod vbe

in the OS X section of the /boot/grub/grub.cfg file.
Some details are presented here in the Grub2 wiki.
The second method is to just chainload the native bootloader of the OSX86 from within Grub2. This seems so obvious, but the chainload command needs to be qualified as shown in this blog post.
The /boot/grub/grub.cfg stanza that I used was as follows (IOW, I left out the cpu=1 in the original):

menuentry "Kalyway 10.5.2" {
set root=(hd1,1)
chainloader /usr/standalone/i386/chain0
}