Sommerfeld JT (1999), Tracking the Marshal & Swift Equipment Cost Index, Cost Engineering, Vol 41 No 4 p29 gives the M&S All Industry index from 1913 to 1997.
I'd love to have a history of the Mining and Milling index too.
Sorry for the delay - I just noticed that the M&S Mining and Milling Index is included on the Economic Indicators page of Chemical Engineering Magazine. 1Q2007 value is 1427.7. 1Q2006 value is 1368.4.