Here's my muscle anatomy study of Tyrannosaurus, featuring both an adult and a juvenile. Comitting to actually finishing this one has turned me into a bit of a T. wreck...
The idea behind this reconstruction was to show an interpretation of the anatomy with most of the superficial tissues removed, so that it could potentially be built on in different ways.
The original description and historical photographs of the AMNH specimen, casts of various elements that I've been able to look at in museum collections, and this photoscan of the current AMNH mount itself by Thomas Flynn (https://sketchfab.com/3d-models/tyrannosaurus-rex-amnh-50k-a0262d71f65048a48fe1b14062c4ed51) were all useful resources for visualising the skeleton prior to reconstructing the muscles.
Useful dinosaur muscle resources: https://www.dropbox.com/s/zomk6qwjqcn48lt/Muscle%20References.pdf?dl=0

Higher resolution: https://tinyurl.com/y5j5nwnp