Old Lego (Weeping Cross ST17)

If anyone has any old Lego (1980s or '70s maybe) hanging around we are trying to make up some old sets we had as kids now my nephews are getting in to it. We had Pirates, Knights, Racing cars, Space ships, Ice vehicle thingys, Underwater things etc. And some technics - but that wont be 'til the boys are a fair bit older :) Much appreciated, thanks in advance.