Recently, I've acquired a '30s jumbo acoustic flat top by the Oscar Schmidt Co., branded 'Keystone State' (Weymann). It came with some old repairs one of which is a poorly planned and executed back crack repair (solid birch back). The crack was just slathered with what appears to be epoxy, and let to dry. I would like to give the back a much more presentable appearance.
I've managed to scrape most of the epoxy off, and am now considering doing the paint work myself .. I think, because black is easier to work with than a translucent finish. Being a minimalist, I don't want to refin the entire back. So anyone with experience with this?
My question is can anyone with experience outline a procedure for this job? I don't have spray equipment but could source paint in spray cans. I have micro-mesh sanding/buffing materials, including a large arbor buffer.
Check the pic .. it looks worse that in real life

Thanks .. Tom