This reply is mostly for archival purposes in case somebody else is asking the same question...
I got this message from paul g in reference to his earlier post.
“Doh! Sorry mate I just looked at the cush drive and it is bolted on as well!!! although this is pretty obvious really, it was a couple of weeks ago I stripped them and was working from memory at home and I have just looked at the parts in my bench at work. Sorry if I gave you bum info. Paul”
When the sprocket carrier comes off the cush drive you will see the 5 bushings. In between each of those you will see 5 black nipple looking things. These are plastic covers to the allen bolts that are holding the cush drive to the wheel (paul g’s may not have been there any longer since it looks like he could readily see the bolts). Remove those with a little screwdriver (pretty easy to do since they’re just pushed in). Once the allens are exposed, you can remove them. When that is done, give the piece a tap from the other side and it will pop right off.
About the rubber gasket in between. It isn't a gasket. It is just some black RTV in there but it gets completely squished out so you could probably powder coat the whole thing in one piece if you don't want to remove the cush drive. Let me know if you have any questions on the procedure.