Migrating from v1.5-debian1 on legacy server to 3.0.2 on new server

Hi.
I have been tasked with moving Gallery 1.5-debian1 on a legacy server to a new server.

The old server is
Debian 3.1,
Apache 1.3.33,
PHP 4.3.10-18,
mysql-server 4.0.24-10sarge2,
Galery 1.5-1sarge1

The new server
Ubuntu 10.10,
Apache - 2.2.16
PHP 5.3.3-1ubuntu9.6
mysql-server 5.1.49-1ubuntu8.1,
Gallery 3.0.2 from souceforge.net

Note that the on the new server the whole application needs to hosted under a single home directory, as we are running apache Virtulhosts with suexec so each application runs in its own environment. mod_fgid is used in conjunction with php-cgi to server php pages.

I have had a quick look at http://codex.gallery2.org/Gallery3:Modules:g1_import but this looks like both the old and the new install need to be on the same server.

Given the big jump in versions / architecture what would be the simplest method to do the migration ?

Thanks

G