Comparing the descriptions by François Joyaux in "La Rose de France": Bloom: SB: very double, petals large and ruffled, a few stamens, barmine-pink spotted with light pink LPBP: less double, stamens visible, spotted pink, fades to light lilac, some petals have white streaks in the centre Prickles: SB: numerous lightly curved prickles LPBP: some strong hooked prickles Foliage: SB: medium green LPBP: light green
Thanks to your job on the gold standard book about rosa gallica(my favorite book too). I' have both LPBDP e SB in my garden but the difference is really minimal and I have still same doubt. Best regards. Giulio