Some of you may be familiar with the A1 Steam Locomotive Trust's work to build 60163 Tornado, a newly-built Peppercorn class locomotive. The result is fantastic. In the US, a similar group has formed to build a new Pennsylvania Railroad T1, number 5550. They estimate it will cost 10 million US dollars to build it. I hope they're successful, I'm a bit surprised that not a single one of the originals was preserved, running or otherwise, all were scrapped.
http://en.wikipedia.org/wiki/PRR_T1
http://prrt1steamlocomotivetrust.org
http://en.wikipedia.org/wiki/LNER_Peppercorn_Class_A1_60163_Tornado
http://www.a1steam.com/