Hey there, have any pictures of your cover on a non smooth seat like maybe a Russel or a Corbin with a higher pillion seat? Will there be a floppy\baggy gap or is the rider section a tighter fit?
Here is a picture of my corbin (before it got ripped to shreds from daily wear and tear). Corbin wants a ridiculous sum of money for a recover, I could buy a second hand one in perfect shape for less. I think one of your covers would be a perfect choice here.
Also, I think this would be awesome on a velour Russel seat like this one (which I am terrified to actually use and leave on the bike).
While I'm here, here is my leather Russel seat.