What Wild is saying is the best way to clip that would have been to use as much as you can, sleeve the windshield posts and join that whole clip to the car about 6 inches up the windshield posts. You need all that sheetmetal off the new clip anyway. So you have to figure out how to use as much of that intact as you can. So you want to use the cowl from the clip, the area where the door hinges bolt on from the clip, everything. With the clip intact as it is right now, everything on it is jigged up correctly, try to use it without cutting it apart.
The less welding you do, the less parts you have to line up correctly. If you join one big part to the rest of the car, you only have do that one lineup (top and bottom of course). If you start cutting parts off and you have to graft 6 separate parts to your car, it's going to take a bunch of time, the welds won't look factory and chances are a few pieces may not fit correctly in the end.