I've found that when I have films that I haven't tried before, samples or whatever, a form of semi stand or stand development is the route to go. It appears that it doesn't matter much what film it is or how it was exposed, unless you really screwed up and underexposed like crazy.
I usually use Pyrocat or Rodinal, and I mix at high dilution. With Rodinal I do 1+100 at 70*F. Presoak the film for however long it takes to mix your chemistry. Develop for half an hour, agitate for the whole first minute, make sure to rap your tank on the table top pretty hard a couple of times before you set it down to dislodge air bubbles from the reels. Then agitate again at 15 minutes. Two inversions should do it to stir things up again. Traditionally I've used 500ml or so per roll of film to make sure I have enough chemistry.
That seems to get me good negatives almost all the time with damned near any film. It's a really versatile way of developing.
If you really overexposed the film, you can dilute 1+150 instead.
With that said, I've never used Agfa Scala, but I don't see how it would be significantly different from any other b&w film out there.
- Thomas