Replace Swallow with Stephenson's Rocket - Wikipedia
Mallard: https://en.wikipedia.org/wiki/lner_class_a4_4468_mallard
Boar have Mallard skin
Replace Swallow with Stephenson's Rocket - Wikipedia
Mallard: https://en.wikipedia.org/wiki/lner_class_a4_4468_mallard
Boar have Mallard skin
Sprinting
Achieve the highest profit from a single transport.
For single train (maximum per delivery) or for one slot (as in 3 rule - X-slot engine counts as X transports)?
Invest your money in the wagons as loan.