I understand they mined just over 20,000 tonnes in 1981-1982 and recovered about 0.8% tin at the Wheal Jane concentrator. The milling deal fell through so the first company went into receivership. CTM ltd who took over had plans to restart mining there and look at Cligga as well. They put a resource of 1,350,000 tonnes on Wheal Concorde, but surely that must have been more than arbitrary considering the lack of drilling. They said they planned to construct a decline and second shaft and eventually equip the mine to a 600tpd capacity. Whether this was at all realistic or not I have no idea. There seem to be about three significant and proven lodes, north dippers, as well as a few undeveloped ones, average widths 4-5 ft, with tin, and some sulphides.
What kind of development was done on them, along either strike or depth I'm not sure but I wouldn't have thought it was very much. Geologically its been argued that the area is ideally situated and is likely to develop well in depth, but you cant be sure the lodes continue unless you intersect them at depth and along strike. Ive read the odd comment here and there about development underground not being encouraging, but that could mean a number of things.
As people have said above Trounson was very involved in the mine, and its mentioned in Cornwalls Future Mines very favourably along with the general Blackwater area, so theres no doubt it was a very serious prospect, but the work there hasnt left very much to go on. Certainly it looks to have started off very speculatively (pretty good speculation albeit) and whether now considering the results were clearly pretty unspectacular, the overall incentive to even drill what is still a fairly uncertain deposit must be pretty low. I suppose all things considered it depends if theres anything better around.