From the Buffalo Trace website:
“A wheated bourbon with a full-bodied flavor and a balanced palette. Old Weller Antique is bottled at 107 proof, offering a complex taste and bold finish. It’s certainly a recognizable member of the Weller label, with its own unique characteristics to compliment the high proof.”
This is from the 2016 rebrand of the range, which saw the "W.L." prefix dropped from the packaging. In her book But Always Fine Bourbon, Sally Van Winkle Campbell claims that Sazerac did not have the exact Weller recipe until their partnership with her brother, Julian Van Winkle III was agreed in 2002. Undoubtedly a nod of approval from the family for the modern day product.
The Antique is bottled at 107 proof and used to carry a 7 year age statement but this has now been removed. As of 2019 these bottles have been sealed with either gold foil and cork stopper closures or the original screw caps, depending on the intended market.