Western Flyer?

My Mother in Law gave this bike to me a few months ago, It belonged to her Father and she thinks it may be from the late 20's. I have cleaned all of the bearings and repacked them and replaced the old tires which were as hard as asphalt. Aside from this I have onlt washed off the dust and dirt. It is from Western Auto and the badge on the front is labled Western Flyer. All seems original save two bolts that I had to replace and the handle grips which I have also replaced. The sprockets and chain are known as "skip tooth", I am told. I really would love to know more about the bike, so would my Mother in law, who rode this bike when she was a youngster. I am 51, you do the math! Could this bike really be from the 20's? What is it worth? Should I do anything else to the bike to preserve it? I rode it this morning. She rolls well, but it has really tall gearing which makes the hills a challenge. Any help would be greatly appreciated.
Scott