Working with HSV images- any GIMP experts here?

OK at the most simple level I can manage, Just posting the IR luminance chanel (i.e. the Value or Light channel) into another image

original [IMG]http://i740.photobucket.com/albums/xx49/df8/IM5G1254_zpsb8b2baf3.jpg~original[/IMG]

ctrl-L to get layers dialogue in gimp

Get your image and decompose it to HSV, Colours, Components, Decompose.
make the Hue and Saturation layers invisible (prob not necessary).
[not needed for IR]copied the value layer.
[not needed for IR]paste as new image
[not needed ir]on the new image I processed a heavy USM so I could see the difference.
[you copy IR value layer] copy the new USM layer from the new image.
go back to the initial HSV decomposition.
edit, paste into [ you'll see a new pasted floating layer]
[IMG]http://i740.photobucket.com/albums/xx49/df8/Fullscreencapture04042014005550_zps7bd2ca8d.jpg~original[/IMG]
click new layer icon and you will see a new "pasted layer".
[can rename new value pasted ]
delete the old "value" layer.
change the mode of the pasted layer to value.
make the remaining layers visible (prob not necessary)
change the mode of the other layers back to HUE and SATURATION

you should have the two original H S layers mode correct and the new V layer mode correct.

Colours, Components, Compose (recompose doesn't seem to work)
Make sure the layers are matched up and it should work. i.e. you end up with a new recombined image from the HSV chanels.

There's nothing to stop you changing the opacity of the pasted layer and merging two layers, the visible and IR value channels!!!!

result USM editing only the Value chanel
[IMG]http://i740.photobucket.com/albums/xx49/df8/hsv-compose_zpsc7cd8388.jpg~original[/IMG]

learned another thing or two about Gimp

If you haven't already seen it you may care to have a look at https://www.youtube.com/watch?v=zzVXK4eAM5E which is nominally about darktable's equalizer tool but shows detailed comparison steps in gimp working with wavelet decompose layers.
P.S. for any other unsuspecting readers who look at the video - darktable has lots of other 'normal' and friendly processing modules. Its equalizer is a bit (actually a lot) starship enterprisey module that allowing free manipulation in the frequency domain doing opencl-pyramid stuff like the mcclanahoochie link.

Thanks, Doug, that's a great explanation of how to do what I want with the images! I'll have a go at it! Your help is much appreciated.

That video has some good stuff in it, too, Rob, I'll have a look at darktable too, never used it before.

Hope it works for you, would like to see the visible and IR enhanced side by side.

OK Doug, bit busy with work the next few days but I'll try processing a few shots I already have asap...