Since I wanted to use vented disks up front too, I am going to try to adapt 944 (n/a, early) front hubs so a type 1 bearing can be used for an inner bearing and a spacer bushing will be used for the outer (944) bearing as the 412 spindle is a litte smaller in diameter and not the same as a type 1 spindle. It does use the same type 1 bearings though
Here is the adapter ring on top of the still original 944 hub:
This is after the hub was shortenend by 6,5mm and the inner part openend up for a shrink fit with the adapter piece:
After heating the hub in the oven and putting the adapter ring in the freezer, it fell right in
Next job is to install the wheel bearings and try it out on a spare 412 spindle...