As it is right now, this top has "antique" value. Any work done on it at this point will discredit that and it will be considered to be finished as of now.. Consider if you want it to remain as an antique or do you want to finish it and enjoy it as a finished project? My own opinion is to finish it in the method of the time it was created to keep it as true to that time as possible. I definitely would not long-arm or machine quilt it!
That is a beautiful top. I am a hand quilter and enjoy finishing these projects, imagining the original quilter as she carefully chose the fabrics and spent time putting this together.
Now do you want to enjoy it "as is" or as a finished project? (Please hand quilt it!)