My understanding, based on the above, is original release was ultimately revised to little fanfare.
But the source code release did not reflect that. The X1 release was likely based off that source, and then my graphic patch was further on top of that.
Yeah, my final bug fix is dated March 2010, but the final version of the levels in the source are dated from late 2008 and early 2009. I don't recall the release history but the update may have gone unnoticed. It is for sure a shame the fixes didn't make it into the X1 edition. No matter, all will be sorted soon enough.
Oh, it probably goes without saying, but I'd beta test this in a heartbeat. 
Right on, I was hoping you guys would be interested in testing. Really would like to have a test version ready for you guys by the end of the month, if not sooner.
Got sideways pipes going.. I think I'm gonna add in some trees in levels where they seem to be placed more deliberately vs just random background elements. Then I should be done with all the background changes.
Still need to add in the hammer power up.
also want to explore having mario exit from pipes at different heights, there's a few spots where this causes some big changes, like especially in 4-4
