Grip safeties are older'n Methuselah. Here's one from circa 1815 on a W.H. Wilson, London. I believe it was a Manton innovation which merely blocks the trigger blades. Intent was two-fold: to help prevent blowing your head off whilst loading, and supposedly allowed safely carrying the gun fully cocked for rough shooting. Only problem is I tend to grip the wrist while walking.....not a good idea with this arrangement. (These late flintlocks were often built as self primers as this one is so were loaded with frizzen closed and hammer at half cock.)
