thats something i know about,i helped marino to get his tube bender fixed(per email haha).
after broken tubes of all kinds and many adjustments we came to the conclusion that he HAD to heat treat the tubes before bending,then re-harden them afterwards,so yeah,theyre heat treated 4140 crmo.the weight of the proto forks was around 1112g.but that was straight gauge 1.8 mm tubing.atm hes getting his bender a new disc,in the future there will be fork legs with gauges down to 1.1mm,aprox.fork weight 980g.hot!
edit:just to not get beaten,thats calculated from butted tubing of 1.6 down to 1.1 mm,steerer 240mm,a2c 400