I don't know which model it is, it is very hard to find Columbia catalogs from the 1950s.
Two things to consider:
1: It is a step through frame - a girl's bike - which counts against its value.
2: it has several desirable features, the tank, the light, the chain oiler, all things which increase value.
If it were in excellent shape it would be worth about $200-$300 to the right buyer, which admittedly there won't be many. In as-is condition it's difficult to say because while some of the parts are valuable, the bike itself is not especially valuable. If it were carefully cleaned and polished up, you might be lucky to exceed $100.