Wanting info on gold plated yamaha 581

[Bharville]

I am currently "test driving" a Yamaha 581 flute that is entirely gold plated! Can't find information/history anywhere out there on this instrument. It is sterling head,body and foot and has cy headjoint which I think is handcut. I know it is an older flute and has a low serial number. What's the story behind it and is it a good buy? The gold is "double layer" and was done at Yamaha factory. Help from you history buffs!