Keep showing old node in munin to review data

I am using munin to monitor some servers and now I have delete a server but I want to keep the graphs in my overview to be able to compare the data from the old server to the things that happen on the new server (for example questions like "how many apache accesses did we get in May last year on the main webserver (now delete) and how many do we get now on the current webserver?").

I tried to put

[old.example.com]
update no

into my config but the host old.example.com is not visible in the overview.

I also tried to trick munin into "updating" the host like this

[old.example.com]
address cmd:///usr/bin/true

but that also hides the node from my overview.

Is there any way to keep a node visible where I can not update the graphs any longer because I do not own the server/IP any longer?