Silver Tray ID help

[lisa58]

I have looked for a long time for this one. Closest I have found was on this site where I found a mark for the Harford Sterling Co. The mark is a bit different than that on my piece but maybe is was changed or updated? The images show cover to serving tray, interior of tray showing its detail work and third is the mark: crown over X, square shield with H in top left and S in bottom right inside shield, followed by lions head. Next is a triangle with "Silver On Copper" within. Any ideas?