Riley,
I don't feel your analogy and hence your logic applies here. We're talking about exact identical steering wheels here. If BMW or Porsche were daft enough to reproduce the same exact 60s or 70s cars today they'd cost much more than the original cars due to increased cost of production, inflation, etc. So I'm equally perplexed as Etsy as to why a wheel that happens to have a date stamped to the back of it (out of sight too) would demand more money than an identical wheel sans the date stamp.