i may be wrong but...
the 748s didnt come with the ohlins rear .. as has been said so it would appear that somone has fiited it
this does not necesserly mean that they have fitted a new one, ie post 2001, they may have fitted one off an older model bike such as 916sps for example. the point is there are at two main types of ohlins rear shock which have differant damping curcuits and thus differant settings.
be sure you have the correct ones!!!!for your shock