Script for checking policy

Please have a look at bpimagelist.
Try both these commands for 1 client to see what the output looks like:
bpimagelist -client (name) -d (start-date) -L
bpimagelist -client (name) -d (start-date) -l

Lowercase output will give info in one line that is easier to parse with awk and grep, but dates are given as Unixtime.
-L will give formatted output. Maybe easier to parse with egrep and awk.

I am not aware of any command or script that will only give 'last backup'.
You will need to add your own 'tweaks' depending on the output that you see in some test commands against a couple of client names.