Don't sweat this too much as the starters are interchangeable. The 750W type is also known as permanent magnet with gear reduction (PMGR). Smaller, more efficient, has that tell-tale whine when cranking (you can hear the difference even with the hood closed). The gear reduction is used to compensate for the lower torque of the smaller motor. The earlier 1400W type uses standard field windings to create the stationary magnetic field and has the drive gear directly on the motor shaft.

Only auto trans was available with that engine so you're not likely to find a starter listed with the manual gearbox frontpiece. If you have the smaller motor, be sure that the rebuilder used the long studs needed to attach the rear mounting, or transfer them from your original - one at a time to keep the starter intact.

As far as the ID on your starter - I don't know what is crosses to but if it was ever rebuilt... that housing could have come from any similar Bosch starter and be totally unrelated to your B280.