I suggest you read the following paper:
Prendini, L. 2004. The systematics of southern African Parabuthus Pocock (Scorpiones, Buthidae): Revisions to the taxonomy and key to the species. Journal of Arachnology 32(1): 109–186.
It only deals with Parabuthus species from southern Africa so you won't find P. pallidus in the key. But it gives you an idea on how Parabuthus spp. are IDed. You can follow the key to P. mossambicensis and read the description to that species. That way you should be able to rule out that species. I can help you and take a look at it myself (although I'm 100% sure that it's P. pallidus) but I would need good pictures of the following parts of the metasoma:
- metasomal segment I und II, dorsal
- metasomal segment I und II, lateral
- metasomal segment IV und V, ventral
- metasomal segment IV und V, lateral