Hi Dave,
The list provided me with this projection info a couple weeks ago. I am
using it successfully to draw mapserv images which overlay on top of Google
maps.
PROJECTION
"proj=merc"
"lat_ts=0.0"
"lon_0=-90.0"
"x_0=0.0"
"y_0=0.0"
"ellps=GRS80"
"no_defs"
END
John