stumbled across a sit of a polish/german railway and machinery overhaul and rebuild business...seems they make everything possible. The shown antique "Lanz" tractor is all new. They reproduce all cast parts, engine, everything. Just a matter of what people are willing to pay for it, I think...

http://www.interlok.info/LawiWalzene.htm

scroll down and click "back to start" to view their railway jobs