Dont loose any parts esp for bottom bracket. Its a 26 tpi thread non standard. You can buy them but best to keep the originals. You will need a derailer hanger to use modern derailers or learn how to rebuild the old one. I say its a very worthwhile porject though. Youll love it and hate it all at the same time and learn more than you even think possible.
Just incase something bad happens and you need to replace your bottom bracket
threadless bottom bracket