an english wheel wouldn't cut it.
the steel is already as thin as possible. any thinner and it'd be see thru!!
you'd need to cut verical lines in the existing flared areas of the quarter, and add triangles of steel once the slits are opened up. then weld everything properly, and bury it in as little mud as possible
you'd also need to fabricate a inner wheelhouse, possibly tub it out.
plus the opening in the doorjamb, and the rear door skins would need the same treatment
if you search you might find one on here, I saw a custom steel widebody thread on here a year ago
pretty cool stuff, I do collision work
sometimes I get to do sheetmetal, custom fab stuff every once in a while. (doing a $200k '73 Yenko Camaro right now!)
I'd definately recommend $3000 worth of sheetmetal work than $3000 worth of shitty fiberglass...!