I also seen (C) in some, what do they denote? What can I learn about a patent or application based on its alpha-suffix?
How curious that you're interested in a corset, patented in 1903! The 'A' is called a 'Kind Code' and is different for different jurisdictions, and also differs over time in some jurisdictions (e.g. before 2001, an 'A' kind code in the USA meant a granted patent; after that time it meant a Patent Application). Here's a useful table of USPTO Kind Codes. FYI, it is a real headache for integrated patent system analysis and requires lots of 'binning' to get equivalent types of documents/rights to be displayed.