Not sure what you are asking, but I do alot of sewing and might be able to help if I understood.  

I took the cover off mine, to insert a Saddlemen gel pad, sculpted out the foam some, put in the gel pad, and re-covered.  More comfortable, but still wasn't happy with it.  Then bought a Mustang seat for an older Sportster, but the curve of the seat pan was wrong, so I took it to a local upholstery guy and he swapped the seat pans.  Now I have a Mustang seat on my original pan.  I can give you info on him, if you are ever up this way and want to go that route.  He only charged me $50 and it was a job!  He has also done alot of work for my husband on vehichle seats, etc, and does a great job.

I think I follow....   Smooth the foam with a cheese grater type file... then cover with a single piece of vinyl ... lay vinyl in hot sun or use blow dryer or steam to get fabric stretchy...  
and you end up with this...

Serowbot that's pretty much exactly the look i'm looking for on my bike too.  Want to do a solo seat, but didn't want the bike to look really short and stubby, that fender helps keep the length on the bike.  Where'd ya get that fender from?