Type Fountain pen
Product Name PB-5000. We're not entirely sure of that ID, but it's something very close to that. Please see this helpful post on FPN for Japanese product sheets showing this model. It seems that the PB-5000 was in the top-mid price range.
Manufacturer and Year Platinum, Japan, 1970s. (Possibly 1980s, as this pink is a VERY '80s color.)
Filling System Platinum cartridge or converter. A Platinum converter is installed.
Color Dark Pink with gold trim.
Nib 18k soft fine nib, according to the markings on the nib. Very smooth and springy, with a bit of flex.
Condition Excellent + condition. Some light scratching on the barrel, which is largely hidden in the brushed finish. The feed has faint blue ink staining, which does not affect the pen's function. The trim rings around the barrel and cap lip look great, with no brassing or plating wear. The clip looks good, though with some tiny marks on the edges. The imprints are clear.