Smooth 'noise removed' & non-removed transition [SOLVED]

version Audacity 2.0.6 on Win 7 (64bit)

I have some (very) old 78rpm tracks to audion enhance.

I need to use ‘noise removal’ and can easily do that because at the start of the track there is a ‘lead-in’ with just the needle hiss, etc.
but I don’t want to run noise removal on the whole of the track, because it doesn’t remove just the ‘noise’.

Is there a way I can ‘fade out’ the noise removal, i.e make it a smooth transition between noise removed and non-removed portions?

Tks…

Create an in-sync duplicate of your recording , by selecting it , then pressing “Ctrl”+“D”
Then apply noise-reduction, (or other effects), to one of those two identical tracks.
Then use crossfade tacks to make a fade between the two tracks.

Thanks Trebor,

Much appreciated.