I believe the delica4 uses the T-7 on the small screws and T-8 for the pivot screw.
At Home Depot I got a Husky torx screwdriver (has 4 double sided interchangeable torx bits, so 8 total: T's 4, 5, 6, 7, 8, 9, 10 & 15). It is gray and is like a jewelers screwdriver, you can spin it quite easily. I really like it because as said the bits are interchangeable and it holds the 3 non-using bits inside; it is very handy. It was also very affordable, I got it for around $12 plus tax and it is really well made.