Finished the socket chisel today.
After these photos I cleaned up the steel and gave it a quick edge - I was pleasantly surprised at the hardness of the steel and would guess it is a vandium / tungsten alloy but would love to hear from anyone who knows about these socket 'D' chisels - or another late night of research probably!
The edge was good, it feels really nice and I much prefer the longer handle I have made over the original - gives me better control. It feels Japanese to me.
Just got in from a late night in the workshop - glued a rare earth magnet in upside down with quick setting Araldite AND a brass cover cap recessed on top of it AHHHHHHHHH>>>.....
Drill hole in brass cap with small drill bit then larger drill bit catches in edges to remove it.
Don't waste time trying to drill a hole in rare earth magnets (although the dust does catch on fire which is fun)
SMASH it out - it worked for me.
Just in case you wanted to know....