I read this with some interest and a little trepidation - 80km/h? Max 'cruising speed' according to the manual is 25mph (40kph).
They bounce alot at 40km/h - I would not fancy any axle/ bearing issues with an unbraked - 1 1/2 tonnes at twice this recommended speed.
You are right for long trips - put it on something more modern (truck or trailer) but when towing short distances, be aware of the 25pdrs limitations. Also stop and check your bearings regularly on every trip.
