Fine rose and scroll.

Often referred to as Purdey-style engraving, as that firm made liberal use of the pattern.
Bouquets of roses set in a generous coverage of very fine acanthus scroll.

The style was also much used by Charles Boswell:

...and this Blanch back-action sidelock is a particularly fine example:

Here is an interesting variation on the theme, by Cogswell & Harrison,
on a lovely Victor side-plated boxlock: