There is nothing sacred about original gear ratios, period. As others have observed, custom gearing was common practice. When you have only 9 usable combinations (excluding large-large cross-chaining), you have to pick your cog and chainring sizes very carefully to get good coverage over a decent range.

I remember the Schwinn Paramount half-step: 52-49/14-16-18-23-26, with a gap right where you need some gears. This is something a 6-speed 14-16-18-20-23-26 freewheel, like the one I custom built for my Bianchi, would solve handily. (I use it with a 50-42 1.5-step for general purpose riding, sometimes a 50-47 half-step on flat rides.)

The French were big on 52-45, and my Nishiki came with 54-47. This works OK with something like 14-15-17-19-21, but makes for a stiff bottom gear. I custom-built a 14-15-19-21-28, which gave me 8 fairly nicely spaced gears on top and a granny, but I needed the large-large combination to get something in the low 50s.

The closest thing I have ever found to a decent 10-speed combination is 49-45 / 14-16-19-22-26, but the 10% gaps are a bit larger than I like. I also used to run 50-42/14-16-18-20-23 in my younger days, but I sure like having the 26 added to that now. There is no way I would run the original Capo competition gearing (52-48/14-16-18-20-22) or touring gearing (52-46/14-17-20-23-26) -- too little range in the first, too much redundancy in the second.

I have settled in on custom gear ratios that work for me, which included replacing all of my 5-speed freewheels with 6- or 7-speed units. In the case of the mountain bike with its 8-speed freehub, regearing involved removing the spider pins to liberate the individual cogs for a little mix-and-match, to give me the 12-13-15-17-19-21-24-28 I wanted -- works great with custom 48-40-24 up front.