These were Strathearn's new Limited Edition series designated P8DS and first issued on 1 May 1978. It was to be limited to only 3000 per year. Strathearn used its regular P8 paperweight design for this series with the addition of a "S-date" cane in each weight. Production for 1978 is unknown at this time but there was only seven months left in the year. At some point in 1979 everyone was aware that Strathearn was being sold so production for 1979 is also unknown at this time. I have not yet seen any of these with an "S80" cane and Strathearn ceased all paperweight production in May of 1980. Sizes ranged so far as I've found from just under 2.5" to just under 2.7".
DCP05002P8DS-S78-1
DCP05002P8DS-S78-1