(Note: Measurements are outside max. dimensions unless stated otherwise).
18th Century : Plain insert thread escutcheon.
Height 22mm. (7/8")
Width top 10.5mm. (3/8")
Width base 10mm. (3/8")
Depth 3.5mm. (1/8")
Thickness (variable) 2mm. (1/16")
Height 18.5mm. (11/16")
Diam. of hole 7mm. (1/4")
Width at narrowest part of neck 4.5mm. (3/16")
Width at base of taper 6mm. (1/4")
Usually glued in or could be pinned from inside flange.
There are escutcheon pin fixing holes inside top and bottom of flanged insert.