Nice one. Free is the best kind.
I cannot wait to see photos of this thing cleaned up.
I recently purchased a product that you might try. Only $8. I had a very small surface scratch on the edge on my used KoAloha. (it came to me that way) One swipe and the scratch is gone and it feels perfectly smooth.
I also used it to clean the fretboard on the KoAloha. Wow, it was dirtier than it looked. I will be using this on my Silvertone and Pono when I change the strings.
This has coconut oil in it. Can be used on any wood or metal: