Harvey, the man who rebuild my bw65 says that the rigid band for the reverse is supposed to be placed in a bw65 the bw35 has probably two flexible bands but the bw65 does not. So may be you meant that in a bw35 the bands could be wrong?
I can only tell you what I've learnt over the years. Others have their own opinions, and you're at liberty to choose to believe whatever you want to.