Hello @grosgood
Not sure when I may undertake that rework.
No worries 
Completely off topic…
Your way of explaining computer stuff (G’MIC in this instance) is really amazing!
Whenever I read your posts I am firstly impressed by the excellent English (American) wording of your sentences.
And yes, I am aware you are a native speaker (mother-tongue), yet…
I have read the inventor of the PERL language was a linguist by formation [1] and probably these 2 professions (linguist - programmer) have something in common (either you “adjust” letters or numbers in the end…)