So Cyclegod you seem to be a bit of a Honda hater??
We had these Honda's in the day as new bikes and flogged the piss and pick handles out of them and they kept coming back for more!!
Now as a 28 year old bike I am sure they show some wear and tear but I would be happy to own one (but then again I like Honda's).
The 85 had the increased oil volume (0.9 up to 1.1 litres) and differing frame rails (to compensate) for the engine case change, outside of this they were pretty much the same bike.
Just on the point of the cylinder cracking Brett (brother Brett) had one for years and had no issue, he did also have a 86 model 600 that had the same problem. He did not fix it and had no issue with it. (they would crack between the valve seats, seat to seat).
So on your point of a carry over model they are not as they are not the same but splitting hairs one would think?