This is the kind of job that a body shop with a good line of BS can make rent for at least half a year.

The jig would be fine, however if the front end hasn't been mashed previously, would be an extra effort with diminished returns. I wouldn't use the jig unless the front firewall is damaged.

Start with a good set of body diagrams from the Porsche shop manual. I would block up the car without the front suspension and not move it until the job is done. This would give you enough points to measure and reference each other. Drilling or grinding out spot welds is a pain however worth it. I used a lot of cut off wheels, Dremel tools, a small right angle grinder and any other type of tool that I thought would help. I'm more likely to cut around the spot welds if possible and use them as a guide when spot welding the pieces back together after I've dressed the welds. I used a small 110 vt, Lincoln SP100 with .025 wire for a spot welder from one side. It worked very well. Sometimes I drilled a hole in the new panel/patch above the original spot in the adjoining panel and filled the hole as a spot weld with the wire welder.

In all, this is a job that can be done adequately in a well equipped home garage with very good results. Patience is the key here. You have already seen what the "professional mechanic" has done to your car, could you do any worse?

Do you have contact info for Kurt? I live in Manhattan and looking to connect with someone for basic repairs I need. Thx.