According to the August 2009 Resource Capital Research report, MRO "Seems undervalued at EV/resource ~A$1.50/lb U3O8."
I think that's a general enterprise value per pound as opposed to relating to a particular location so you could imagine RIO Puerco delivering a better EV as the mine is essentially ready to go if conventional mining gets the nod. It would also seem likely that uranium wont be this cheap forever and any increase in spot price would equate to an improved EV.
Anyways, if current enterprise value per pound is realised, Rio Puerco should equate to $16.5m AUD for MRO. Okay, noting current market cap, but doesnt sound like much compared to the sales value you identified. Time will tell but I agree it has to head North sooner than later.
The report also says "Monaro appears undervalued" [at 8c].
MRO Price at posting:
9.0¢ Sentiment: Hold Disclosure: Held