The type G guard should be bent so it is crowned or radioused in crossection when viewed from the front or rear. The guard on the Williamsburg owned gun was attached by the tang bolt upward threaded into the barrel tang, with screws in the rear extension. Originally I bet it had nails as the guard was repaired long ago at the bow. I have seen a original trade gun with a nailed on guard extension. Due to the use of screws on the Williamsburg gun I suppose you could do it either way. The guard should be surface mounted. Tip, bend the end of the extension and the finial down slightly before final installation of the guard, this will prevent the ends tipping up away from the stock after installation. BJH