The 'gravure' described there is modern day 'photogravure' where the 'image' is effectively etched onto a plate, creating 'dots' which will be defined by the grain of the film negative.

I was referring to old fashioned (sometimes called engine turned) engraved gravure, as still used for bank notes, where an engraver makes a die which is hardened and then pressed into steel plates for printing. More like the 'engraved' depicted.

Either way, I do not accept any of those processes were used to create either of Greg's inlays