Polaris 400

Hi All,
I collected a Polaris 400 last night, and to say it needs work is an under statement, no brakes, leaking diesel, no lights, gearbox broke into 3 nees the casing welded , and dont know if that can be done, just looks very rough, but she runs, how can I tell the year I am told its 1994 and where do I start do I just take off all the covers and clean it down, and start with the gearbox then onto cables and brakes, I live in Ireland so nearest dealer would be the United Kingdom Thanks if you can offer advice.:sigh1: