After reading on Pelican how much of a PITA this was I was filled with apprehension, but nonetheless picked up a few do's/dont's from reading all the threads.
Unfortunately the old two-stage screen from my 72E resto proved to be u/s - shame because it had the old Porsche Club of Hong Kong Championship sticker on it that I'd have liked to retain from its racing heritage.
Anyway after some searching I decided to go 'new' and ordered a replacement from Porsche - £475+VAT to you sir
First job is the wiring. The window has three arrays, top, middle and (you've guessed already!) bottom. Stage one just fires up the middle array and this is supplied by the red wire with the white trace, pulling for stage two then uses the red wire with the black trace and fires up the top and bottom arrays to cover the whole window. So first job is to connect the top and bottom arrays with a piece of black wire of the exact length (so it fits snugly in the rubber surround) on the side where the conductive strip down the side is split into the three arrays - you can just see the splits on the far edge in the photo above, and on the one below. The conductive strip down the other side is continuous and this side is the earth connection.
Now Porsche in their infinite wisdom decided sometime in the late 70's or early 80's to switch the side of the three split conductive strip sections from the LH (early type) to the RH (later type) - so this means if your wiring is from the early type (like mine) and you buy a later screen (like I did) then you need to modify the wiring - basically the earth wire is too long and needs shortening, and the red/white and red/black wires are way too short. I decided to make a join where the wires enter the engine compartment and made up some new accordingly.
OK now onto the preparation of the seal itself. If you dig into the recess that the screen will fit into you'll find it has two separate sections
The section nearest to the outside (where the ally trim strip fits) is for the window, the other is for the wires. Now you need to decide where on your seal is the bottom LH corner, and punch three holes for the wires from the recess near to the lip you eventually will coax over the screen edge on the car, and into this inner groove. I found clamping a thin piece of wood into a vice and using a hole punch worked well.
Feed the three wires through
and along into this inner groove
It takes a bit of measuring to determine the right spot, but obviously at some point the wires have to transition into the outer groove so they can attach to the male connectors on the screen edge. About 20mm short of the connector I cut a small section out to allow this to happen
Then it is just a matter of getting an assistant to stop the seal snaking all over the place while you connect the wires to the screen and fit the seal around the screen per normal fitting. Get the ally trim profile right and fit it into the slot on the outer face of the seal. I find using my fingers and the heel of the hand best and you can feel the trim 'snapping' in. Fit your strong cord of choice, and you are ready to fit
After reading on Pelican best advice was to fit the top edge first - getting your helper to press forward (he was in the engine bay and this worked well!) so as to assist the seal to stay over the lip at the rear of the cockpit ceiling. Once you get most of the top edge done it is vital you use a pick or something to ease the outside of the seal up out of the recess towards those thin slots above the rear screen edge. This will help the screen move forwards so the rear edge will go down into the bottom recess and ease the seal lip going over the bottom window edge on the shell.
We had one small bit of ally trim come out in the top LH corner, but 'persuaded' it back in
Then fit the wires into a piece of sleeving and down the hole into the engine compartment
Refit parcel shelf and done
Again my thanks to Garry for his help - this is another definite two-man job - three would be better, but alone it is inviting disaster.
Hope this is of use to someone.
Mick