Help needed cleaning adhesive & more

[Roonie]

(Small bit of context to preface: I have NO CLUE what I'm doing. Never worked with leather before. All I know is neatsfoot oil good, and keep things dry)

Hello! I recently thrifted a leather jacket and cleared off the previous owner's patches. They used a considerable amount of adhesive, which has left behind quite a bit of residue. The sleeves' adhesive had hardened, and when I went to peel it off, it looks like it might've taken the topmost coating on the leather with it. It was upwards of a millimeter thick in some places, and dried pretty rigid, but I was able to get the worst of it off. The two backpatches' residue is a little gooier, and still tacky. I've heard talcum powder can be used to clear that, and I'd like to confirm the validity of that method.

In general, what solvent or product can I use to clear off the adhesive without wrecking the finish on the jacket? Or is this something I should bring to a dry cleaner?

For that matter, what should I look for in a dry cleaner or repair/cleaning shop to make sure they won't damage the jacket? (And if anyone has recommendations for places in central jersey, I'd appreciate knowing where to go)

I put pictures of the jacket in this folder.

Thanks for any advice you have!

-Roonie

[Handstitched]

My first thought was toluene , thats a thinner for contact adhesive, but I'm not sure what that would do to the leather underneath.  Acetone 'may'  work  but that might take the colour out of the leather . The other stuff I thought of is ' Eucalyptus ' oil' but might not be strong enough. It may not be available where you are.  Perhaps try a little bit of toluene in an inconspicuous  spot first 

HS