Agree with your assessment that any takeover (if one were to materialise at this time) would not happen for less than $0.60.
Based on today's GL1 price, the value of the whole remaining elements of the GL1 deal (inclusive of residual 20% of Manna) for BRB is circa $77m. At $0.60, BRB would have a market cap of $200m - so after deducting cash + GL1, leaves a residual value of $115m for 1.7m oz plus the Ularring prospect with its PGE targets. Hence the residual equates for a value of AU$68/oz even if we ascribe no value to Ularring and no value to the likely substantial upgrade as we drill out in between the step out holes, etc.
For me, this remains a "bottom of the draw" hold, as something will break on this sooner or later that will create significant value from its current levels.