I am replacing internal doors with fire doors due to having a loft conversion/builing regs. I wish to retain my original BRASS door handles. These handles have two screws that go right through the door and fit into a blind threaded barrel (as opposed to 4 secrews per handle per side). Because the fire doors are thicker than the old internal doors the existing screws did not fit as they had to be cut to size to fit the original door thickness. I have managed to get some longer brass screws to accomodate the thickness of the fire doors...so no prob there. My problem is I have two doors with bathroom type latch/locks that you twist 90 degrees to lock. These are now too short to fit the thicker doors. Any ideas where I can obtain new ones that can be cut to length. The metal bar is 5mm square and the lock twister (for want of a better word) is held on the bar with a small grub screw. I think it may be possible to get the 5mm bar and swap the twister and the slotted head (which looks like its pressure fitted) on the other end of the bar onto a longer bar. Anyone come across this problem before?