It appears from these links to the 1982 models that the Bridgestone model designations are ASP 530 and ASP 560 for the 700c wheeled bikes.
Links to a Japanese website Cyclotourist:
1982 model designations:
1982 model geometries and specifications:
The above are for the 1982 model year and I believe my particular bike was from 1986 based on the component dates and the bike having the later style Sugino PX cranks.
I acquired my Bridgestone Atlantis in not so bad condition considering its age. It has some light rust but no dings or cracks or any structural issues. Some of the chromed parts such as the headset, the pedals and quick releases were a bit more severely rusted but these are replaceable and not a great concern.
It still has mostly the original components. Original parts missing were the fenders and the front rack and the original seat binder bolt (replaced by a quick release by previous owner).
The first picture is of the bike when I got it and the second picture is its current configuration:
I have been looking for the correct front rack which is supported on 4 points (2 at the brake posts and 2 at the mid-fork lugs). The Nitto and Velo Orange front racks on eBay are configured to be supported on 3 points. Those though not optimal, would do and I probably will end up with one of those.
I am also thinking of having the shifter on the handlebar for easy access. However, I still have not made up my mind whether to go indexed or just use friction shifting which would cost much less and will not necessitate changing the rear freewheel and rear derailleur.
I am also toying with the idea of putting one of my Grand Bois Hetre and Velo Orange 650b wheelset on the bike paired with my Mafac Raid brake:
There is very little information about the bike on the internet and this is because this model is only marketed in Japan and there were not many made.
Here is a write-up of the same bike by Grant Petersen of Rivendell Bikes and the man responsible for making Bridgestone USA famous among bike enthusiasts during the late eighties to early nineties.
Links to a Rivendell fans site Cyclofiend:
The bike does have similarities in geometry and details to some Alex Singer (and Rene Herse) randonneuring bikes as observed by Grant Petersen.
It is also apparent that the Bridgestone X0-1 material and design has its roots in the Bridgestone Atlantis. The quad butted tubing, the investment cast fork crown, the simpler V-shaped rear dropouts (without the small triangle) are similar. The geometry is likewise not too far removed; with tweaks probably due to the wheel diameter difference (700c on the Bridgestone Atlantis and 26" on the later Bridgestone X0-1).
Owners of Rivendell Atlantis bikes who are still wondering why there is that number "2" painted on the seatpost of their bikes should wonder no more. It is there as a tribute/acknowledgement to the first bike named Atlantis.