OK. I think I see. Does the shop you work with butt weld and grind so that the weld is not visible. If so, then yes that will take a lot longer than a lap weld. If you don't want the weld to show at all then I agree that the one-piece floor is best. However if the goal is to just get a structurally sound floor and you don't care about the weld then a lap welded set of right and left pans goes quick. I lap welded mine and didn't dress the weld at all before priming, seam sealing and painting. I personally would only care about the weld showing if I were building a show car or doing a concours restoration. If not show or concours I'm all about which costs less since either approach yields a structurally sound floor.