I have experience with ferrying Beechcrafts and Snow ag planes to and from Europe and Mexico. Usually, a fuel cell was added in the back seat area or chemical hopper.
Ag aircraft are routinely ferried to AUS
with extra tanks and routing for fuel stops along the way. Very long navigational hops over water are made easier nowadays with GPS equipment. When I used to make such flights, LORAN was just coming about and was much more complicated as it was usually a permanent installation than usually portable GPS units. (Now, GPS units are a permanent must for ag aircraft as it eliminates the need for flagging crew and ensures accuracy in placing chemicals in the correct areas.)
Usually, most GA
aircraft are shipped via boat and assembled in AUS
. That is why there is a great demand for A@E rated people in those countries.
If wishes were horses, a Tail Dragger I would fly...