Since it's parts and put together and never been "proved" anything is possible. Wrong bell/ pivot / fork, etc real hard to say. You might have to measure some of the parts for length to the pivots, and either get help from guys on here who have known good parts, or contact Brewer directly.
Please do NOT discount the idea of a bad / mismatched clutch PP or disk. Are you SURE the disc is in correctly, should have the "large" (raised) part of the hub facing rear. In my lifetime, myself, and two friends, I've seen at least three new, out of the box PP that would not release or operate correctly.
The fact that you are describing the pedal "has pressure 3/4 to the top" seems to indicate that you need more length for more depression of the pressure plate. Are you saying that there is a large amount of "pedal" at the top that is not doing anything?
