I've worked out a workflow for getting manual focus lenses EXIF fields set into Aperture.
It's a bit of a round trip using applescript and ExifTool, but it gets the job done.
My workflow is outlined here: http://photolifetoys.blogspot.com/2012/08/manual-lens-data-exif-to-aperture-quick.html
Wondering if LightRoom or other tool has anything which would make life simpler??
What steps do you take to get your manual lens metadata into your libraries?