I think it was Jedha Patrol who pointed out the massive difference in saddle size HT vs SSC. HT saddle looks to be at least 3X bigger, but that probably just comes down to it being a Mando style saddle whereas the SSC one is the SE/PT saddle.. Neither the HT nor SSC saddle or belly straps are even vaguely correct for ANH, but the saddlebags sort of cover it.
I wish someone would have posted some closer side by side pics of the HT and SSC Dewback heads - the SSC head looks larger in relation to the body and the HT is the reverse, where it almost seems slightly too small for the more chunky body (even if it's possibly close in size to the SSC head.)