Jerry Moos suggested:
<snip>
If you want to go for minimum cost, you can push an NR RD to a 28T FW with a 52-42 front if you get the chainlength just right and push the hub axle to the very back of the DO's. You might, maybe, handle a 30T FW if you also reduce the large front chainring to maybe 48T to cut down the range shifted. That would eliminate the need for a new BB axle and new RD. Plus you can probably find someone happy to trade you a 48T ring for a 52 or 53.
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Back then, those of us of limited means simply went to a half-step (front shift half the ratio change of rear step, so front "tunes" rear selection). If you use a 13 - 31 FW with a 5 tooth split in front, you can keep the Campy NR or old-style Record RD, keep the BB, and just ride. For example, the "Orphan" uses a 13-31 Regina on a Hi-E or Weyless hub (different wheels), usually with a 40-45 Strongight 63. With that set-up, she has useful gears from 34 to 93 gear inches. There are hills here for which that's not low enough, but not a lot of them. But, we were younger back then...
harvey sachs
mcLean va