One of the obvious ones would be the building of A1 Pacific No. 60163 'Tornado' from scratch.
The A1 Steam Locomotive Trust built a brand new main line steam locomotive in 19 years (from project launch) at a cost of £3M & has been successfully running the loco for the last 9 years.
They are now in the process of building an even bigger engine!
www.a1steam.com
Tony