The single Weber was originally made for a round port head & it has had some minor porting done on it giving it an oval port look, just like he says in the ad.

The twins are not SU's at all but Hitachi's instead. It bears the appearance of being either a composite GX induction, or a very early B210/120Y setup & the manifold is clearly for the large oval ports of the GX.

It looks to be quite incomplete & is even missing the throttle cable mounting bracket.
None the less, it's the basis of a workable GX induction, although the chances of finding the GX air filter assembly would seem fairly remote these days.