The fore end iron for a standard beavertail is different from a splinter iron because it is made for a reinforcing screw that comes in from the front. All standard beavertails use a roller latch, and the thumb piece of the latch is longer than for a splinter because the fore end wood is thicker. I have changed a splinter to a beavertail on one gun, and it required making and threading a block of steel to the front of the fore end iron, then silver soldering it into place to accept the reinforcing screw. I also had to make a new thumb piece for the roller latch from a piece of flat steel stock. All in all it was a lot of work, but worked out well.