This is a peculiar recording. I had already in my library two versions of this dawr (both of poor sound quality) and probably both Odeon takes, one by Hilmi in bayati from the beginning, including the dulab and the long introductory layali with hardly a slight variation in shuri, and one all the way in saba without any modal variation by Sulayman 'abu dawud. My guess is that Hilmi here, either purposefully or unconsciously, produced a mix of the two versions. In fact, what he does is to change his mind in the last minute; the dulab is in saba, he starts the short layali in saba and from the first notes of the madhhab he moves to bayati with a transition that hints to rast,. But, in my view, it is neither rast nor dalanshin. Once he's gone in bayati, he doesn't leave it till the end. Another trick of those to which we are now accustomed from 'abdi-l-hay.
Could you kindly upload a raw copy?