had to get a few pieces out and start taking snap shots and measuring. i have an adjustable stud mount bridge (that i would not use) but one that i would use as a template for making the stud slots and the piece to mount under the Badass. this bridge is slotted on one end which makes the stud mount holes expandable from 3 5/8" to 3 3/4" center to center.
the Badass bridge (an original
NOT the 2, 3, or 4 type) would fit between the stud holes with a little careful machining of 1/32" off of each side. the Badass measures 3 1/8" wide stock and the bridge measures 3 9/32" closest hole edge to closest hole edge. the Badass is flat on the bottom which would simplify machine work.
what does an early EB series measure center to center stud to stud? this bridge is string spaced at 2 1/8" so it would be a natural to use as a plate pattern. what i am calling "hole edge" here is actually the edge of the washer ledge and not the hole the stud fits through.
it could be an alternative other than trying to find a Schaller 460 that isn't beat all to heck, missing some parts or overpriced.