Tolgus has a very long and chequered history! I went there when I was at CSM, in the 70s, at the time it ran on run-of-mine from Pendarves, or burrows dirt which could be bought very cheaply in unlimited quantities.
Even the burrows dirt had enough tin in it, especially as any tin extracted was put back into the cycle so there was quite respectable quantity in the loop.
TBH, I think the combination of its isolation at one stage by the construction of the bypass, competition from and manouevering by the Wendron/Poldark operation relatively close by, and lack of interest has combined over time to sadly degrade what could have been quite unique. It's a pity that something of the sort couldn't be incorporated at Geevor/Levant where it would, at least, have a chance of being seen and maintained.
plus ca change, plus c'est le meme chose