If you read the report it clearly states that the trustee simply...

If you read the report it clearly states that the trustee simply used the 31.12 market price as a proxy for "fair value".

There us no magic to the number and it certainly does not reflect any analysis of value. In fact, the same report goes on to recommend against the takeover offer.

Extract follows:

The SPS Trust has invested in preference shares issued by PaperlinX SPS LLC, a controlled entity of PaperlinX. Investments are initially recognised at fair value plus directly attributable transaction costs. Subsequent to initial recognition investments are measured at fair value with movements in fair value recorded in the condensed statement of comprehensive income. The fair value of this investment has been determined using the market capitalisation of the SPS Trust based on the closing price of the SPS units at 31 December 2013. Refer to note 2(d) and note 9 for comments in relation to the uncertainties that exist in respect of the carrying value of the investment.