Having read about the differences between the two editions I was wondering if it would be viable to simply add five tokens/cards to the first ed. to represent the junction contracts, and play by the 2nd ed. rules.
I know the board layout has changed, but is that such a big deal?
The board is certainly the biggest change. Some of the cities have changed color, and although I still need to try it I believe it has been for the better. But the changes should be relatively easy to make yourself with the aid of a printer.
New boats are merely cosmetic.
New cards on slightly heavier card stock. Only two minor changes: a junction card for each player (easy to make your own) a player aid for each player (replace the original two)
New, greatly improved rulebook.
Strangely enough is the new TRIGGER (end game) tile not supplied(!)
All in all a nice upgrade kit, but I wouldn't call it essential.
It should certainly be possible to use the new rules with the old board, the one proviso is that some of the colour changes have been made to fit in with the use of junction contracts. For example Bristol and Gloucester are now different colours, making it a viable option to create a junction between the 2, which would be no use on the old board as they are both green.