Hey Johnny (from Mississippi), the 1929 models had the four-tube muffler, two tubes on each side, then went to the two-tube muffler in 1930 with two stacked tubes on the right side. You're right, both 1929 and 1930 had dual headlights........beautiful bikes back then, huh?
The rear brake Fiskis and Steph are talking about had a 5-3/4" diameter shell that was 1-1/4" wide through mid-1929 (for the 45's) then widened to 1-1/2" for the late 1929 & 1930 45's. Then from 1931 through 1934 the shell and bands were increased to 7" in diameter by 1-1/4" wide. The "new" 1931 bands had a "-23" part number since they were the same bands as were used on the 1923-1929 "J" models. This makes sence during the depression since the tooling was existng and dealers already stocked them. Fiskis, I'd love to see you '30 BAF!!!