The LB8's, like their base LB7's and sibling LB5's, came with both types of bolsters. Clemente says they are NS, and they were for the most part. NS was just a bit fancier in appearance, though a tad more expensive material wise. When they switched the LB5 from nickle silver to brass bolsters, it was said to "maintain a stronger 'family' look". However, it doesn't take a manufacturing expert to recognize that design and material changes are generally driven as much by cost factors as much as by quality and appearance.
Michael