I would go with 12-24 hours per fender to do it "right". That is to get them on the car in my definition of right, Everyone's right way is different. For the factory racer look, it was most likely less than 30 minutes per fender. Why because well we here to win races, not beauty contests.
For the level of work people seem to want to now put into these cars, not bashing It, just say it is disproportionate, it would easily take 12 hours, and people would say wow those are really nice. But the best way is to butt TIG fusion weld the joint, no filler rod, and hammer each and ever weld point, get them all done, planish the entire thing and they end up looking like this.
Click to view attachmentClick to view attachmentClick to view attachmentClick to view attachmentNo filler, no wrinkles, just one solid piece of metal perfection at it's finest.
This guy's work can be found
here and
here. If these ONLY took 12 hours of shop time I would be surprised.
I know a few that can make the entire fender from a flat piece of metal. They will bring insane prices to the table, but their rates are spot on, it is just it takes insane time to produce this stuff by hand.
What it comes down to is your level of expectation and what your willing to pay to achieve your desired goals. Case in point, I was looking at a Ferrari 250GTO KIT the other day, the body looked great, all the proper bits in the proper places. Got it on the lift and I
looked at my friend and said if you buy this car I will beat the living
out of you. Everything that was "custom-made" on the underside of the car was pure crap. Fitment was crap, welds were even crappier, and lest not even begin to think about all the other crap I would end up fixing this car. Car was already on the high side of his budget for a fun vehicle. I estimated it would take 80 plus hours, to repair the crapmenship in the car. And that was the crapmenship I could see. Only the original builder knew the quality of work that was done. For me, my level was much higher than the original builder. My friend passed on that dressed up pig. I am sure he will drag some other POS into the shop for review at another date.
Every time someone does a high end build the bar gets raised. What you don't see is the many ways to get to the finish line. I could do it in 30 minutes per side, the repair could last for years or maybe 10 minutes. I could spend 1000s of hours to get everything just perfect, side to side front to back etc.... Only YOU can figure the level you want out.
I built one in the 90s for a friend and he insisted on fiberglass flares, to get them to look correct, I spent way more hours than I documented. Hours upon hours down the drain. Only to have him drop it into a ditch out here, and rip the left rear off.
He should have spent the $$$ for steel. And at that time I would have MIG'd them on and we would have been done in like 6 hours per side. The car was being built for him, to his level of expectation, not mine. And he was paying for that level of work. MIG, grind, filler material put in, sand down, then paint.
I would also say Chris and Mark can do them in 12 hours because they have done more than 1 set in their life. Double or triple their time for your first one, and then the time will drop off on the other 3.