Question about "canon characters" for custom models

[Fawfulthegreat64]

I was thinking recently, there are some characters that are undeniably official parts of the media in question, but are never directly seen. This obviously would mean they can't have customs submitted, as the design would be 100% fanmade.

But what about characters who have been seen visually, but in a limited way? For example this is obscure information, but Blumiere's Father from Super Paper Mario is not 100% lacking an official design. His silhouette can be seen in the Super Mario-kun adaptation, and it reveals key elements of his design such as a large mustache and bowler hat. Would a custom model that is consistent with those design elements, and fills in the blanks with elements of Count Bleck's design, be eligible for being on the site? This also applies to the "Blumiere" design shown in a silhouette and reveals some design elements his "Count Bleck" form doesn't have, like a nose, non-jagged mouth, and hair. Timpani also is seen in silhouette form (with clearer details than in the game)

 

To what degree would making models based on this source material be acceptable? Because I do have an interest in exploring these designs.