Someone wrote "Buy a decent bit".
I concur.
Spent extra time tonight, while modifying a desk, looking for some
'Torx'.bits.
Finally found them but none would fit the odd looking screw heads. I hadn't
really lloked at the screw heads and was having trouble with a slightly
worn Roberston bit!
Closer examination showed the heads had an unusual eight point design to be
used with a 'regular' Robertson Number 2 (Four side Canadian; in GOOD
condition)!