I had manual trim in my -4 once with the quadrant basically in the same spot. I just ended up making the trim lever shorter and bent it such that it was inboard the throttle quadrant but not so long that the end of it would be even with the mixture control (had a fixed pitch prop so no prop control).
While I'm sure it was more sensitive than the installation shown on the plans I didn't find it too much so. Eventually upgraded to electric which is what I prefer. In a perfect world I imagined a trim wheel controlling manual trim with an electric motor/clutch offering the best of both worlds.
If it were me I'd install a short, manual lever and go fly. If you don't like it you can get more adventuresome in coming up with more complicated solution later.
PS - my manual setup used stock mounting brackets on lower end - just the lever was modified.