In correspondence, a sister from Jews for Jesus pointed me to this panel discussion on Christology in the OT at SBTS. The discussion is hosted by Dr. Thomas Schreiner, panel includes m'man Dr. James Hamilton, author of a wonderful book on Biblical Theology (among others), Dr. Duane Garrett, and Dr. Peter Gentry.
It's a good, solid, helpful discussion, with a few sparks here and there and more than a few helpful guidelines.
I'm saying this half to share with you, and half to bookmark for myself!
Postscript: for any who don't know, my talks in a British conference on Messiah in the OT can be found via this post.