re: Three really large 18th century style chisels

they are definitely big. the style is odd for that size, but they're about as big as the big old English gouges and flat chisels that were probably intended for housewrights-  or who knows what-  but like the older english style that's more familiar (turned handles, tang, Butcher or Ward as the maker, etc), they're thin and not heavy like timberframing tools.