It is hard to say what the origin of this frame is. Especially when comparing the little bits that saracen were a bugger for changing to suit the situation. Part bin raids seemed common practice bitd.
My money is that it is the same a longuns frame (kili pro 96) and has been meddled with a bit by Saracen and or someone else.
Ritchey tubing/curved stays would suggest 96. And the cupped dropouts definitely do. Lack of canti noodle etc.