Off topic again.
I removed my starter motor last week, the bolts are 8mm allen type. I used the irwin bolt extractor to grip the outside - it was a lot easier than trying to use a key or socket.
The alarm ECU is on the right hand side of the fusebox under the steering wheel. There is a coax type plug which is the aerial connection, follow the lead, I think it goes into the A pillar.
It's not the infamous spring is it? If you hold the interior button up whilst opening the door does it work? http://www.landyzone.co.uk/lz/f8/disco-door-springs-how-101126.html
Have a look at http://www.landyworld.co.uk/discowindows.htm for your window poblem.
If you are sure you don't want to get heavy handed with the garage can't your daughter have a quiet word "without you knowing"
Have you got a small red light directly underneath the radio? If so you have remote locking and alarm. Before getting a remote you need to know which frequency it operates on 418mhz or 433mhz. The fob is a single button one. Have a look athttp://www.remotekey.co.uk/cars/Land-Rover/default.asp for all the info you need. If you get a single button fob you can code it youself.
Have a look at the Technical Archive under the manuals section, you should find all you need there.
Without going into detail about body changes, the series II disco is a 5 cylinder diesel so you can tell from that.
There is an inertia switch in the c/l ECU - http://forums.lr4x4.com/index.php?showtopic=73791&st=0&p=631084&hl=+inertia%20+switch&fromsearch=1entry631084