There is a reason the Octalink Bb has been moved on from. To get the larger diameter spindle inside the same diameter shell Shimano used much smaller diameter rolling elements, which do wear at a faster rate then larger diameter ones, all other things being equal. Additionally many feel that the sealing of these BBs isn't as effective then the tapered square units.

Now I would ask if the slop/play is a functional issue. Does it effect shifting? Does the chain rub more now then when first assembled (and the der cable tension adjustment having been kept up with)? Bearing slop/play that doesn't effect other functions can be considered a non issue in many cases. In fact most radial contact/preassembled/cartridge bearings need some end play to avoid premature wear.

The only Shimano Octalink BB that is adjustable for end play, AFAIK, was the Dura Ace version 1st generation. Shimano went away from this design soon though as the floating bearing cone would cause creaking and sometimes crack. To give Shimno credit they were trying to solve the problem of poorly maintained tapered square crank arm retention bolts and the resulting arm becoming wallowed out and coming loose. That they could also claim a stiffer BB spindle sure helped in the market place, too bad this has so little actual benefit in real life. Andy.