That was well before my time...although granted, I didn't really take up the sport until the mid-80's.

The only time I had two different weights of pins in play was a regional in Savannah where the tournament director had the PBA Gold Pins in some of the racks for the practice block and was considering having us bowl on them instead of the basic traditional white pins.  Personally, I liked the Gold Pins but had a look with both types (same pattern on all lanes)...unfortunately that was also the tournament where I broke my hand in the first game of qualifying.