It's gorgeous. And will look beautiful after you love on it.
Now, a rambling discourse on process: Everybody kind of does their own thing and uses different products, but there's a basic core set of actions. Dunk/soak/swish around the bag in soapy water in a sink with dishwashing soap. (People here like dawn.) Scrub as needed--I use a toothbrush. Rinse in clean water with white vinegar added (kills mold). Wipe down with a towel. Shape with your hands and stuff bag to reshape. I use bubble wrap and towels to stuff and reshape. Use Leather CPR while still damp (pretty universally recognized here as the best product to use). Follow directions on bottle. Let dry, change towels, etc. I let it dry and then use more go-rounds of leather CPR, with a day or so between application--depending on how dried out the bag is. Your bag, I would touch it up with brown leather dye on the scrape areas--I use Kiwi leather dye (not polish). Finish with a product called Blackrock Leather 'n rich. Buff wildly. Polish the zipper or any brass (I use brasso, and do this as a last step). Some people polish the brass first, in case they spilled any which needs to be removed from the leather. Carry the bag proudly.
Other repairs may or may not be needed. I use Angeles leather filler for rips and edgekote for cracked or missing pieces of edgings. I like Aileen's leather glue as well for glueing. When something needs resewing, like reattaching straps, I turn that over to a professional cobbler or leather worker. PS: some people (I don't know why), prefer saddle soap to dunking, and are afraid of getting the cow wet.
I would approach with a few minor variations but don’t want to bog you down as what Connie and whateve suggested is quite solid. What I will say is that this style has a place in my vintage loving ❤️! I will add that I dunked one in navy, at least one in black (had 2, don’t recall if I dunked the 2nd) and a camel (stunning rehab failure!). I had no issue with the lining for dunking (full submersion in water) and drying for any of them.
) on the hardware of any I've rehabbed, but I use jewelry polishing cloths instead - on the rings, zipper teeth etc. Cape Cod polishing cloths and some other foam type polishing pads, from Amazon. 
