/3/ - 3DCG

I'm trying to model a face with poor references: one front view and a 3\4 portrait style view.

I have no information on the camera used, focal length, lens or anything like that.

Other that fucking around randomly with scene cameras to try and get it right, is there any method or utility that can be used to at least get it in the ballpark? The few I've found through Google only seem to work with architectural photos with plenty of orthographic lines to reference.