Use *.rad extension for all 'xform -rz 105 -rx 90 -ry -42 -t -13.9 0 -30.7 -a 2 -mx -a 2 -mz -i 1 -t 17.55 1.499 42.2 -t 9.75 -3 0 latch+nut.rad >> tmp.rad' include lines.