Matching ebony with ebony

I've got an old maple cue with ebony butt that I had lengthened years ago with 4 further ebony splices. the ebonies are very slightly mismatched.

I'm going to get the cue refinished and wondered if there was a way (not painting!!) to get a uniform jet black finish for all of the splicing so it's impossible to see it was altered?

Any advice would be appreciated. Cheers

Matching ebony with ebony