Assay office gouge marks?

I have a George III silver rectangular milk or cream jug, London 1806, maker’s mark too rubbed to identify. The bottom of the jug has definite gouge marks as if someone has scraped a sample of silver from the item. Could this be the work of the assay office, testing the silver content? I have not seen this sort of gouge on any other item. Did the assay offices actually remove metal from items in order to test them?

This is not an assay office mark. Although they removed a small amount for testing, when the silversmith got his piece back he would have made good any minor defect.

Thank you Phil: it’s pretty strange damage all the same…