Ok,hello every1-first of all,i m back and very glad about it:))-i m not going to repeat any of the pre said about the HB kit l m going straight to the point-so,i ve seen many original pics with open engines and i see the turtleback magnetos,any1 knows when they start to appear on Invaders?ww2 or Korea?,and in what blocks?-likewise the disc brakes with the 6 piston calipers are they rescent (K and air tankers or restored a/c or they appeared sometime in wartime?-thanks in advance