thanks everyone - installed packages have now reappeared - I pressed check for updates and then when I clicked again on 'installed' - they reappeared!
Here's what I have (with version number next to it):
anacron 2.3-2
at 3.1.18
auto-unprotect 2.0.2
betaftpd 0.0.8pre17-4
busybox 1.20.2-1
bzip2 1.0.4
chasedecrypt 0.1.0-0
chaseget 0.1.2-1
cifs 2.6.18
cron-daemon 1.18.3-4
curl-command 1.0.0
dbupdate 1.0.0
e2fsprogs 1.42.13
epg 1.2.8
exfat 1.2.6
fan 1.0.0
ffmpeg 2.8-1
file 5.0.4
fuse 2.7.6-1
hmt 2.0.10
hwctl 1.0.0
id3v2 0.1.11-1
inotify-tools 3.14
ir 1.13
jim 0.77
jim-binary 0.76
jim-cgi 0.7-1
jim-oo 0.77
jim-sqlite3 0.77-1
jim-xconv 1.0.0
lamemp3 3.98.4
libpcre 8.37-1
libreadline 6.2-1
libxconv 1.0.2
lighttpd 1.4.39-1
lsof 4.87
mplayer 32726
multienv 1.7-1
mvdisks 0.3
ncurses 5.9
nicesplice 1.8
ntfs-3g 2013.1.13-4
nugget 0.99-1
openssl-command 1.0.0.d
opkg-beta 1.1
procps 3.2.8-3
recmon 2.2.1-1
rsvsync 1.1.12-1
samba 2.2.12-6
service-control 2.5
sqlite3 3.23.0
ssmtp 2.64
stripts 1.4.3
swapper 1.0.1
tcpfix 1.0.0
tcpping 1.1
tmenu 1.22
trm 1.1
tweak 1.0
virtual-disk2 2.0-2
webif 1.4.4-5
webif-channelicons 1.1.27
webif-charts 1.3
wireless-tools 29-1
zeroconf 1.5-2
anacron 2.3-2
at 3.1.18
auto-unprotect 2.0.2
betaftpd 0.0.8pre17-4
busybox 1.20.2-1
bzip2 1.0.4
chasedecrypt 0.1.0-0
chaseget 0.1.2-1
cifs 2.6.18
cron-daemon 1.18.3-4
curl-command 1.0.0
dbupdate 1.0.0
e2fsprogs 1.42.13
epg 1.2.8
exfat 1.2.6
fan 1.0.0
ffmpeg 2.8-1
file 5.0.4
fuse 2.7.6-1
hmt 2.0.10
hwctl 1.0.0
id3v2 0.1.11-1
inotify-tools 3.14
ir 1.13
jim 0.77
jim-binary 0.76
jim-cgi 0.7-1
jim-oo 0.77
jim-sqlite3 0.77-1
jim-xconv 1.0.0
lamemp3 3.98.4
libpcre 8.37-1
libreadline 6.2-1
libxconv 1.0.2
lighttpd 1.4.39-1
lsof 4.87
mplayer 32726
multienv 1.7-1
mvdisks 0.3
ncurses 5.9
nicesplice 1.8
ntfs-3g 2013.1.13-4
nugget 0.99-1
openssl-command 1.0.0.d
opkg-beta 1.1
procps 3.2.8-3
recmon 2.2.1-1
rsvsync 1.1.12-1
samba 2.2.12-6
service-control 2.5
sqlite3 3.23.0
ssmtp 2.64
stripts 1.4.3
swapper 1.0.1
tcpfix 1.0.0
tcpping 1.1
tmenu 1.22
trm 1.1
tweak 1.0
virtual-disk2 2.0-2
webif 1.4.4-5
webif-channelicons 1.1.27
webif-charts 1.3
wireless-tools 29-1
zeroconf 1.5-2
Unfortunately, I don't have undelete installed - so that option is not available to me.
I haven't yet started recording anything new to the new Humax.
here is how my humax is displaying current files (from webif)
and

Just to recap - here's where I'd like to end up:
since I've bought my 2tb drive, I'd like to install the new 2TB drive into the new (2nd hand) Humax and be able to play the previous recordings from my old 1TB drive (ideally with the names of the movies/recordings - or I can go through each one and rename it I suppose?).
I'd then like to be able to record new movies/tv and be able to easily back them up in the future!
I'd be very grateful for a idiot's step by step guide to the best way to do this!
Thanks again!