My first try at making a 67 'vert lid was done just like yours Max.
The problem of doing like that and welding close to the inlets is that the metal warps and the job of straightening the lid is a pain in the butt since you can't get to every part beacause of the supporting "beam" on the inside that the hinges is mounted to.
Thanks to my friend Tomas Andersson, who managed to locate a genuine one for his own Cal look '67, I got the exact location of the inlets. The inlets are both by shape and position incredibly similar to the ones used on the 70-71bugs. I'm pretty convinced the factory used the same tool to make both.
For my second lid and in order to avoid warpage of the metal closest to and get the position of the inlets right, I therefore chose to cut the upper section of the '70 donor unit off in one piece for the transplant to the '67 lid. The curvature of the two is not near the same, so a lot of bending and test fitting was necessary to make them line up. After a whole lot of work the pieces was finally tacked together.
You can have a look at it at:
http://user.tninet.se/~xnf969f/minabilar/min67/baklucka1.jpgI might add that this was done well before the article in Hot VW's was published
I also drilled the spot welds holding the supporting "beam" away and removed it while doing this operation. All this to be able to get to every part of the lid for welding, grinding and straightening.
A lot of work? Yes, but the fact is that this method uses less amount of welding than the first one and since you never get close to the inlets, the end result is a lot better.
The irony in this is that when I was finaly done with my home made 'vert lid, I managed to locate a genuine one....