anyway to automate applying a custom pallet to an image?

[gimpuser2000]

I have thousands of images to process. I would like to apply a custom palette to each. 

So Alt-I > M > I brings me to the custom palette menu

all that's easy to automate with a mouse macro even

but the rest isn't easily automated. i want to apply the "Grays" default palette to the image

and then i have to scroll down and use the search to find "Grays". it will always be the "Grays" palette.

then click convert

I would like a one button solution. 

1. load the image
2. click a button to apply the "Grays" palette < this is the part i want to automate
3. do my edits to the image
4. save it

can this be done with python maybe?