Tier 3 & 4 emission levels ?

[GMTRacing]

What will the effect of the new locomotive emissions standards be on museum/tourist railroad power? We are already suffering because we can no longer use home heating type oil due to new regs, will this affect us further? In reading the law as passed mandating the reduction in diesel emissions, I see no mention of an exemption for museum or preservation pieces. Does anyone know better?    J.R.