It seems that leather covered pads go back to the late 1890s.
All makers of best guns offered them. In America, Fox supplied the XE grade guns with a leather faced (not fully covered) Silver's pad as standard, but I've never seen a fully covered pad from any other maker except for Winchester. Winchester's leather covered pad, however, was as much an abomination as the gun that wore it.
For reference, here are some photos of leather covered pads that I've done.
The first two photos are the same pad, before and after the cover.