the patina and blue dial, just great.
Regarding vintage Panerai, I do not know one that did not have a black dial, but there were discolorations from gray through tobacco to brown/tan. There is a 6152 owned by our friend Eng that under certain lighting can show a hint of blue but the dial is definitely black. I wonder if that's the one you mean?
There is also a great pic by Nicky of her 87 on a killer strap. I hope she reads this and can post that beautiful pic!
Cheers,
Asi