So, today was a better day. With the right tools it was easy to slide on the drivers side clamp. Passenger side lower clamp was however still a struggle and it took met at least 30mins with different approaches to get the clamp on. Main issue is that the expanded diameter of the clamp is just enough to slide over the hose. However, the hose slides over the pipe, expanding it a bit. Now it is really hard to get the clamp over, especially in such a tight spot. I loosened the subframe (again) to create a bit more working space. Did manage in the end though.
From that point on I could continue hoses and pipes up to the radiator. Passenger side radiator mounted up again and both side have the plastic air channels also back in place. At least some progress today.
Just for fun, a picture of the 1997 base cooling pipes in the wheel well:
And the current setup. Sorry about the flash / non flash comparison, but you can especially see the difference at the bottom right where they come from under the car into the wheel well.
Next step is to check whether the front stabilizer needs some paint before it is mounted back, then assemble this and put the subframe and reinforcements back in the right places. Still work to do in both wheel wells before I mount the front suspension.