We have a osteological chart with 5 different members of the group of Tyrannosauridae from the late cretaceous period with only scales preserved and those various size some a large as a laptop so i dont know where you got the idea of a postcard. The Newest updated version - Tyrannosaur skinchart"not to mention all the feathered ancestors the rex had" Specify all?. Two species of a basal Tyrannosauroidn nested in proceratosauridae not member of Tyrannosauridae -shows filamental preserved, one of them is Yutyrannus Huali and in the scientific of the paper itself there has been no evo devo conducted of the filaments due to its preservation. Have you read the paper you would know tis
The other taxa is Dilong wich is now a free roaming Taxon due to its brainshape conducted in was not that of any Tyrannosauroid but resemble the form and shape of maniraptoria so the taxonomy placement in the phylogeny and evolution in the parsimony tree will more than likely exclude it.
And for "feathers" so we are going to call them feathers if if they dont morphology,/correlates known for accommodating modern feathers avian?.
We just slam some terminology on there without any proper research of the integumental structure itself to test a possible homology - composition.
We do know about the various integumental structures but if we dont know what they are made up of it is straight up wrong to collectively call them feathers or a direct analog to proto-feathers.
For example psittacosaurus which according to fairly recent work (Mayr et al 2016) failed to establish any homology between them and feathers. A primitive charachter that might have evolved once.
I never argued for the anatomy of the JP design i know it is majority inaccurate argued for the integumental structure.