OK.....I think I understand what you are saying. With reference to the front movements: Note that the "inner tracks" will slide within the "outer tracks" when the clip is depressed... the knob that you allude to in the photograph will not affect that movement....take a look at the following review:

http://www.largeformatphotography.in...asterview.html

Note the reference to a "trombone" type of situation.

Are you saying that the front knurled knob has no "purchase" when you tighten it?

By the way, judging from photos, you might also benefit from installing some thin cork sheeting on the metal edges of the piece that holds the lens boards and which is moved to supply axis tilt. Although the cork is not absolutely necessary, many here have installed such cork and I believe the axis tilt mechanism does work much better when the cork provides the added friction

Perhaps others on the thread will chime in as well?