Weller Centennial bottles from the 1990's Heritage Collection come in a 'British' bottle, you can differentiate these by the embosing on the bottom of the bottle. MikeV knows the particulars better than I. They have a Louisville label. This whiskey is accepted to be S/W.
More recent bottlings have a Frankfort label, a domestic bottle, and are BT whiskey.
I've recently been drinking what I shall call a transistional bottle. It has the old English embosed bottle but the newer Frankfort label. It does not taste quite like S/W, and definitely not like BT whiskey. I think it has a Bernheim flavor.
Did BT get some Bernheim wheat in the deal and use it after the S/W ran out and before their own distillate was ready?
"The only way to drink Bourbon is straight, and preferably straight from the barrel."