The gem also looks like it really needs a repolish - would it be worth doing for an emerald of this size and quality? And if so, who should I send it to? Dana?
No, I would suggest leaving it alone. Old prongs like that tend to be kind of stiff and with them being thinned out towards the tips the chances of mauling them during stone removal is pretty good. I also doubt that a repolish would do a lot for the stone and could cause problems in polishing. Nice looking stone IRL!