You may not like this, but . . . Why not send direct to refinisher? Need for you as a middleman? What do you get out of it?
You need to decide if you are running a business, if so . . . record keeping (better) needed, correspondence (better) needed, and require contents lists on all packages. All correspondence needs DETAILS -- not only "what" but "how many". Photos are worth many words.
As the middleman, I would put a lot of this on you, but refinisher is not off the hook. Cue owner does not love his cues as much as I love mine. Refinisher needs to send confirmation of receipt.
Live and learn (get better at it).