All Ludwig 6 plies were a Maple/Poplar mix. They used poplar as part of the shells up until the introduction of the Classic Maple line which was much later on. Poplar made up the majority of the 3 ply shells too (the fat center ply was always poplar) so it is a big part of the "Ludwig Sound". The idea of "all maple" shells being a desireable thing didn't really begin to take hold until the later 1980's. The Rogers XP-8 series were the first to advertise that in a big way and it kind of took off from there until today most everything is all maple all the time, but prior to around 1985-1990 it wasn't given that much thought by most drummers. Top of the line current Ludwig Legacy series drums....there's poplar in there.
If that blue snare were close to me at $200 or less I'd be mightily tempted to snag it and another snare is the last thing I need.