A paper that might provide a basis for discussion is
PETCHEY, Peter; INNANCHAI, Jitlada. 2012. Bottle Top Capsules in New Zealand Historic Archaeological Sites. Journal of Pacific Archaeology, v. 3, n. 2, p. 1-16. Available here or here
Abstract: Bottle top capsules were applied over the cork or stoppers of many 19th century bottles to guarantee that the contents were authentic. They were manufactured from tin-plated lead foil, and were often embossed with the name and trademark of the bottling company. The capsules were discarded on opening, so they are directly associated with the actual consumption of the bottle contents, and used capsules are regularly found in small numbers in archaeological contexts. This paper explores the use of capsules as an additional tool for analysing historic glass bottle assemblages in New Zealand, with a particular focus on determining the actual rather than assumed contents of particular bottle forms. It also presents a typology for use as a reference tool for analysis of capsule assemblages.