John,
For me, if the barrels had holes where the front rocker-box studs come through, it would only have made it more complicated when I was in my BSA infancy to find the nut that I had just dropped while trying to get it on the end of the stud. After enough frustration, I discovered that I could do the job fairly easily by putting some heavy grease on my pushrod comb and using it as a sticky nut platform. (Intentionally delivered in the dead-pan comedic style.)
Richard L.