HKS003 may have hit upon something here.
I built a SSQA to 3 point hitch converter several years ago. This allows me (among other things) to attach my york rake to my FEL. I haven't used it for vines in a tree, but I have raked out shrubbery and such from stream banks and cleaned out ditches.
Because of the curve of the teeth I can see how it may work. Once the vines are dragged to the ground they could be picked up for disposal with about any grapple. If this would be the only use for the rake, It could simply be welded directly to a SSQA plate and the 3PH converter would be unnecessary. You wouldn't need a high quality rake for this application and teeth could be removed if desired to increase the spaces between them. Reach would be about 14ft, I'd guess.
Thoughts?
OP,if you want to see what it looks like, I would be happy to connect it together and submit a photo.