I got access to better scaling and photographiv documentation of the Spinosaurus type specimen, so along with Jaimie Headden's observation [link]
that one of the presumed sacrals was actually an anterior caudal, I set out to revisit Spinosaurus.
Of course much is still unknown, but with the help of Irritator (including Angaturama) and related animals like Baryonyx and Suchomimus I feel like the general proportions are probably about correct, although there is room for uncertainty in the pectoral girdle, forelimbs, and (to a lesser extent) hindlimbs.
Edit: Tweaked the scaling on the head, as well as the rate of drop-off in the distal caudals. Ironically the animal stays about the same length, but the slightly smaller head will have consequences for people trying to estimate the length of the longest specimens.
Edit 2: Now with actual update.