Kentish Paul
Member
It might actually cost more than the Flying Scotsman. The technology involved in a steam engine is well understood and the parts are relatively easily made in a well-equipped metal workshop. The APT probably used electronic components that haven't been made in 30 years and which would be very hard to reproduce in the small quantities required.
Woudn't be allowed anyway. It's akin to getting the Concorde prototype out of the FAA (Fleet Air Arm) museum at Yeovilton and getting it flying again.