I have a HW-19 MK3 with a black platter,the spindle and bearing are part of the platter. I just picked up another platter, the spindle and bearing are seperate pieces. Which one is the newer version?
Your MKIII platter just looks like it's all connected, but the platter will "pop" out of the spindle. Use a rubber mallet and a block of wood to seperate. You'll actually hear a "pop" sound when it dislodges.
The old MKIII platter is "pressed" onto the spindle. Once you break it free using the method above you will neet to reseat it if you want to use it again. Use your 2 piece clamp to do this. It should give you enough torque to pull the spindle up and seat the black platter firmly again.

Check to make sure all is level though once you do this. There could be a little wobble in the platter (it is a machined fitting so not perfect). If there is then just unset them again, turn the platter 1/4 turn and reseat it. Keep doing this until all is level and smooth.

Thanks for that information!
Bob brings up some very good points.

Back in '97, when I purchased my HW-19Jr, the 6lb frosted acrylic Platter was like yours, the Bearing-Spindle was a press fit, and I never felt inclined to somehow seperate it, for fear of knocking the surface runout of the platter out of whack, and then have a possible wobbly platter.

Lubrication maintainence was no more difficult in this scenario. Mark