What's revised on the Fine Molds Type 61? Will there be a revised etch set as well?

Also, will the Modelkasten tracks fit the Fine Molds kit? I believe they where made to fit the Tamiya kit.

Revised in this case means the kit represents the late production improved version of the Type 61. It includes a searchlight for the night-version, though I don't know if it includes anything else or if the modelkasten track fits.

So, the original kit is still considered correct, but representing an earlier version?

Thanks for your input.

That is correct, first kit is early version while the "revised" (upgraded) is the later type.