Hello all. I am completely new to this forum, and new to leather furniture ownership.

I recently purchased a used leather sofa that I want to attempt to repair for my home

The previous owner has apparently used some sort of "water based" dye or finishing product to "fix his old sofa." After putting whatever product this was on the sofa, it made the back upper area very sticky.

He then told me he thought he could fix it by putting an "oil based" sealer own it. He couldn't identify either product, but said they were both made for leather furniture. The sofa's headrest is still very sticky and shiny.

Can anyone recommend any products and/or steps I need to take to fix this headrest. The color is dead on, and he said he used this product all over the sofa, and the rest of the sofa is fine? Thanks for any suggestions. I hope this is in the correct forum as well.