Help with SSH2 and tunneling X?

By way of introduction, I've been to two meetings but I'm
new to the list. (howdy, KevinO)

I'm on a quest to access machines at my work securely from
home over a public VDSL connection. I'm sick of battling
VTUN* so I've settled on tunneling X through SSH2. That
works relatively dandy from my firewall but I'd much rather
use my main box which is on my home subnet.

To get the X traffic to come through I'd have to set my
DISPLAY variable correctly and/or find out how to do some
sort of trick network address translation.

I tried 'export DISPLAY=192.168.0.2:0.0' just to see if masq
could handle it - I also tried setting it to my firewall's
address. Anyone have a suggestion on how to proceed? I'd
appreciate it a lot :-)

For the sake of discussion, this is my network
configuration:

firewall: VDSL connected to eth0, addr 247.123.45.67 via
DHCP
firewall: hub connected to eth1, addr 192.168.0.1 mask
255.255.255.0
FavoriteBox: connected to hub, addr 192.168.0.2
WorkBox: addr 141.190.8.55, static address

ip forwarding and ipmasq work on the firewall. Everyone
involved is running Redhat 6.2 and latest SSH2.

* in a perfect world I'd be able to create a "type ether"
tunnel using vtun so I can move IPX/SPX as well as TCP/IP
via USWest's network. I can establish the tunnel OK but
getting my traffic routed through it isn't what I'd call
"obvious"...

TIA,
Steve Smith