Do you know the weight of the prey that you are feeding Toby? My ball, Cleveland, is just a little bit bigger than Toby (about 400g). I've been feeding him "small" rats for the past three feedings. I buy them from Petco (they are gourmet rodent brand, I think?). The package says they are 40g, so that's what I have been feeding him once every seven days -- I have just been going by the 10-15% of the snake's body weight rule of thumb.
Anyway, just my $0.02 -- I'm definitley no expert, but it seems to be working so far...
Later,
George
BTW, Deliahla (sp?) is beautiful -- definitely a nice looking normal!