Hi All, just wanted to provide an update for anyone finding this topic and wanting help.
first Buster which is in testing has 3.27 available, at time of writing. Sid has 3.28 I used Buster to install.
1) Edit your sources.list from /etc/apt directory to include
deb
http://ftp.debian.org/debian buster main
2) run apt-get upgrade and apt-get update
3) Now you can run the install as
apt-get install -t buster calibre
4) It takes awhile to install including all the dependencies
5) Now you can start the content server (BTW it took me awhile to find the install under usr/share directory)
6) type crontab -e
7) enter a line
@reboot calibre-server --log=pathtolog pathtolibary --daemonize
replace pathtolog and pathtolibary with your locations
that should be you up and running.
I still need to see if it is possible to run the wireless device to sync the changes back or if I still need to do this via a PC.
hope this helps someone else.