A bit more on this... today I found a footed bowl in the same pattern, again not marked, but this time having the decorative ridges running down between every fifth scallop. So the ridges have been altered depending on what the form of the item is...
Putting the feet of both the celery and the footed bowl together they are identical in size but the celery has 24 rays in its foot base star, whereas the footed bowl has 28 rays.
Dimensions of the footed bowl are height 5½" (140mm), top diameter 5¾" (145mm), foot diameter 4" (100mm), 30 scallops round the rim, 6 panels, and 12 round circles.