Pedal box is a lotus item, and ought to be repairable if you have one that is?
Steering rack is from Mk1 escort sport, it's made by burman part no is right hand drive - RHD 7H4101 - left hand drive LHD 7H4102 this is easy to find , check out the Ford escort sites - cost ought to be 30-40 UK pounds.
I don't want to try and talk you out of your project, but and it's a big but the parts you listed are impossible to find, even the standard 5.5J lotus steel wheels are real hard to find in UK, in Germany well all I can say is good luck.
If you sell all the parts you have then you will almost have enough to buy a complete car, I wish I had sold my project and saved myself plenty of hassle. once again good luck, I have many spare S4 parts but none of those which you list. out of interst I'm still looking for the bonnet lock, which has proven impossible to locate. Ihad to make an original looking stering wheel and horn push which is important for the look of the car. - lety me know how you get on - good luck