RE: Making large sheets of balsa help please
Steve: Your plight is not much different than here in N.A.
Those big sheets always seem to be advertised, but seldom in stock. They often cost about 3 times their equavalent smaller size. Joining or laminating are the fastest ways to get going.
Then, you can also consider going to thin plywood, as big sheets there are more often the norm. We have a local place which sells 60" by 24" lite ply for less than one sheet of big balsa, and they will cut to size while waiting.
Wm.