looking at the condition of the bag from your photos, and seeing the brass, it almost looks like it was cleaned and polished before you got it. And may just need maintenance. So, yes, a little leather cpr and/or blackrocks on the piping and the occasional touch up of the brass with either a brass polishing cloth (less gloppy mess but milder in results) or I use Weimans, Wrights, Brasso, they all work. The beautiful thing about this type of old
Coach leather is, it can be protected with Obenaufs, etc. but the leather can be wiped off after it gets hit with rain, and generally if it hasn't soaked through , causing the dye to "run" and make a water mark, they are pretty hardy in all kinds of weather.