I picked this up from my neighbor today. He believes it is a '59 but isn't 100% on the year. I think I will be leaning on you guys a bit for some guidance on finding parts like bearing and races.
You can get a bottom bracket set from Amazon and many other retailers for less than $20. You are looking for a set with a one piece crank. It will have the cups, bearings, washers and nuts to rebuild the bottom end. This is the first video in about 12 videos in the series. This guy goes through the whole process very well step by step.
Great middle weight! The headset you need will be 32.5 cups. Crown race will depend on forks (either 26.4mm or 27mm). Sunlite makes each at very reasonable cost.
Another one of those cool Schwinn twin bar frames! It shows up in the 59, 60, and 61 catalog. The serial number on the left dropout will nail down the year.