Welcome to the forum and the hobby-slash-addiction!
The C-19 "Chippendale" is one of the workhorses of the Edison Diamond Disc line. You'll find lots of info using the search feature on the forum. I'd start by looking for posts about rebuilding your reproducer and making sure the stylus is still good and not damaging your records.
Diamond Disc springs are among the longest and strongest springs out there. It's possible to remove, clean, and replace them, adding new grease when you're done, but it's not a beginner's job and is quite dangerous if you're not very careful - and very strong. As a stopgap, you can try just adding new grease to the spring barrels. After a few times through a full winding, the bumping will probably go away.
Don't worry about overwinding, there's really no such thing. From a dead stop, my C-19 takes about 110 turns of the crank to be fully wound. Yes, really, 110.
There is a "Yankee Trader" section here where you can post info on what records you want and what you have to trade.
As for dating your machine, the C-19 was in production from 1919 to the mid-20s, but I'm not aware of a more specific date and serial number chart.
I hope that answers your initial questions. Like I said, there's a lot of really good info on the board, so search away and ask questions too!