TU3CP rocker adjusting screws

[RadimZ 0]

Hey, question about rocker screws. 
I'm putting a reground camshaft in my TU3CP and because of that, I've bought new rocker arms (Febi bilstein 18351). They should fit according to the part number and they are also the same size. The problem is that they came in without the screws that push on the valves. The screws from the old rocker arms are significantly bigger as can be seen on the photo. 
Is it possible to buy smaller screws that would fit my rocker arms?

Thanks.

[Thijs_Rallye 86 4 Cars]

Why not drill and re-tap? But start checking the rocker arm lengths, I believe there are a few length variations throughout the years, which could spell trouble. This bolt size difference works as a red flag for me that there can be more differences.