Posted By:
warshawlawRebacking caramel cards of Wagner with T card backs is an old-school forgery effort aimed at passing off the final product as a T206 Wagner. The process was chronicled about 25-30 years ago when a similar card surfaced. It was tested and the card came apart when soaked. Assuming both sides of the card are real, my guess is that the forgery was made in the late 1970's.
The most you will ever get from SGC in terms of non-numbered grading is an "AUT" (authentic) on a rare but low grade card, if you request it. SGC does not grade "REB"; the poster above is correct that the listing deceptively places a rejection label into position like a real label then photographs it. Since SGC labeled it rebacked, my guess is that the two sides are real and we are dealing with a late 70's T206 forgery.