That curved seatpost makes me think Elgin but if you send some pics to the guys at www.thecabe.com they'll help you out. www.ratrodbikes.com is a fun place to hang out too.
On a bike like that I like to rub the whole thing down with boiled linseed oil and bronze wool, then wipe off the excess. It fights the rust, puts a little shine in whatever paint is left and still looks like "authentic patina".