@MrBig:I am not sure if you want advice on buying new tires or not from your post.But here goes
The stock tire for the 800's up until the early 2000's is bias ply
I had Dunlop bias plys on my car.The radials come in 145/70 R12. The Indian brands MRF,Ceat,Apollo and Jk have it in that size.I'd stay away from Jk.
Bridgestone have 145/70 R12.They also have 165/60R12 which is the wider upsize for the 800.
Goodyear has 145/70R12 and the 155/70R12 too.The 155/70R12 can be hard to find.I'd suggest you contact Varun for this, he is using this size tire currently.
Michelin makes 145/70R12 and 155/70R12.The 155's are a rare commodity and extremely hard to come by.The old Michelin XM1 and XM1+ used softer compound and sidewall punctures were a problem with them.Not sure of the new XM2.The grip levels and handling is best on Michelin due to its softer compound.
I am using Bridgestone ER60 145/80R12 which came with the alto.It gives better mileage, the only problem with this is high speed cornering where the higher sidewall flexes more.
If the roads you frequently drive on are bad go for MRF or Bridgestone.These are harder compound tires.
If high speed driving is your thing go for the wider 165/60R12.Bridgestone Potenza GIII or Yokohama A539.Yokohama is the cheaper of the two.
Fill your tubeless tires with nitrogen.The benefits are tremendous.