howto reduce size of a debian base system?

["Geronimo Ma. Hernandez" <geronimo013@gmx.com>]

Hello,

I tried several ways of debootstrap, even using --exclude parameter, but I 
found no way to exclude an essential package from being installed.

For example I want to install a base system without gzip. Not for having a 
final system without gzip (wich would be quite silly), but by replacing gzip 
with a link to busybox.
I could i.e. create the link by using a hook in /usr/lib/base-installer.d

If I create the link to busybox after installing the package, the space of the 
binary is freed. But if the binary uses a shared lib, which is not used by 
any other installed package, that space keeps wasted.

Is there already a debian way to build a compact base-system by usage of 
busybox?
Or how can I create such a system?

Do I have to patch debootstrap or Packages.gz?

Any hint is welcome.

kind regard
Geronimo