I've got one that would do for a boat that size - I am not quite as happy that it is the right one for my 36ft. 7 tonne boat though it has held it for the past 12 years apparently.
Yes it dismantles. Looks a bit like the yacht cradle portable jobbie to the point that I asked them if it was an earlier version - which it wasnt.
The piccie show some of it. The yard at which the last owner kept the boat was very exposed so they decided to double bank the cradle. That said I dont think it is up to the 7 tonne weight of my boat though apparently it was properly designed by an aircraft engineer for the first owner and as I have said has been used for 12 years without problem.