You should for sure check the battery, if it shows signs of leaking
replace it. If it is not leaking it might need to be left on for a
while to charge the battery. It a coin type battery it might be flat
and need replacing, probably not though.
To check the buster revision open the case and look for the chip
marked Buster. if you see a -11 that is the good one! If it is not
-11, it might be surface mounted and be tricky to upgrade -7 and -9
are the more common problem ones. Buster can effect some cards that
use DMA only -11 fully supports this. If you plan to get a Graphics
card or run other zorro cards as well as a Graphics card a -11 is also
good to have.
Kickstart 3.1 roms are good to have too, early 4000s had Kickstart 3.0
roms.
Hope your 4000 gets there soon :-)