No investor or shareholder should be using to 2013 feasibility study to determine company value. Confirmed by this statement: Also

Readers are cautioned that the Schaft Creek Joint Venture has completed several additional studies since 2013 and is undertaking an in-depth investigation of the Schaft Creek project in 2019. The results of the in-depth study may differ materially from the 2013 Feasibility Study. The information, assumptions and projections used in the 2013  Feasibility Study have changed since the date of the Feasibility Study. There is no assurance that the economic analysis, reserves and conclusions set out in the 2013 Technical Report will be realized.

Also there is this important information and explains why our inferred resources differ from Teck's inferred resources of Schaft Creek metal content:

The resource remodelling confirmed that there were no material changes in the Measured and Indicated resource categories used in the 2013 Feasibility Study and the 2017 work.  Changes to the Inferred resource category were primarily due to Whittle pit constraints, classification of material and legacy issue related to historical precious metal analysis.