On the B41/B51 controversy, I agree with Barry on '70 E-bodies. If the car had power front disc brakes, both codes would show on the broadcast sheet, but only B51 would show on the fender tag. B41 and B51 will both show on certain tags (1971 through 1973 St. Louis B-bodies for example) but not on the 1970 through 1972 E-bodies. 1973 and 1974 E-bodies with power front disc brakes show only B41 on the fender tag.
Different MoPar assembly plants would show different equipment codes on the fender tags. Lynch Road and Jefferson tags show very few equipment codes on their tags. Some codes never show on fender tags, such as power steering, wheels and wheel covers, or heavy-duty suspension.
Ty