Well for what its worth:
The 968 is a very hard conversion and requires the making of a frame around the front to a except the fenders and front panel.
You can adapt the 968 FRONT complete. Of course the lights and that sort of stuff are something to work out, You could do fixed lights inside the pods, lexan covers, lot easier than those pop ups.
But dealing with the meat of it:.
You will need two pieces of metal to bolt the fenders to, these will be laid across the engine bay to form a V the fenders will bolt to this, so locate the attachement points for the fenders in the door area, secure the fenders temporarily with them laying on the car, locate mounting points, etc, you will have to move the radiator over flow, etc.. a few things that would now sit under the fenders. Some stuff Can stay. The hood hinges are basically the same, I would use fiberglass for all of this, save weight and pick up some good looks. These metal strips should be solid enough to secure the weight and stress.
Now once you sort the mounting points secure the afore mentioned strips, now align fenders and drill and tap the strips, secure with the same type of fastners as stock. Please note the v nature of the fenders will covers some areas of the engine bay, but clearance issues are not a factor. You relocate a few non-critical pieces so that you have access to them.
YOU CAN DO THIS ON THE 924 as well.
Once you sort out the fenders and align the hood, you have to do the nose and bumper... since these areas are very very different 924/944 vs. 968. I think one other consideration, one piece, reverse hinge with quick disconnects and hood pins. Simply mold and attach everything together mocked up on the car, take off reattach, with suppors and build frame for it to rest on. See pics below for more details on either way to go.
WHAT A 968 SHOULD LOOK LIKE IF YOU ARE GOING TO CONVERT THIS IS WHAT YOU WANT TO END UP WITH WIDE AND BEAUTIFUL. CAN USE 944 WIDE BODY quarters, attach 968 rear, then 968 fenders with flares and mold in (note the non-stock front nose and BOOST!):
CUT AWAY:
ENGINE BAY OF 968
Jim Grady - 1988 944 TurboS converted to 968 TurboRS looking bodywork - Race engine by JME - 450bhp @ 15psi boost, 520bhp @ 20psi boost - 2503cc - PCA class GT3R, Weight 2250lbs:
944 WITH 968 FENDERS AND NOSE (note the radiator and other minor mods) Basically remove area around radiator, washer bottle moved to drivers side.:
