That wasn't an oddity. It would have shipped with Workbench 1.3. I had one just like it with the Fatter Angus chip that could address up to 1MB of chip RAM, although you could still configure it as 512K chip and 512K fast, which is what I did.
I can't remember whether you did the 1MB chip config with a dip switch or by cutting a track on the motherboard - I think it may have been the latter, which is probably why I didn't do it.
I can't remember whether you did the 1MB chip config with a dip switch or by cutting a track on the motherboard - I think it may have been the latter, which is probably why I didn't do it.