I have a large ding where the bottom of the take down limb meets the riser...ding is on both limb and riser, and wood is raised on both parts.
It looks easy to sand flush...question is...
what spray finish can I use to seal the sanded parts that will blend with the original finish, and how many coats.

thanks

With out pictures can't comment on the ding.
With out knowing what the bowyer used hard to,say what is compatible.
Shellac will,stick to anything and anything will stick to it.
Then could,spray some polyethylene after shellac.

Yep -- photos please.   How large is a "large ding"??  Have you had it apart to see if there is any damage between the two pieces?

If you are not sure of the finish you can apply several coats of superglue to the area to seal it. light coats and steel wool between coats.