Due to helping transcribe the books at the Manx Museum, I often see writing that can be difficult to read and will spend some time checking the lettering from previous entries.
I have to write what I see though and even when I know that the word should read such and such, you have to follow whats wrote.
The original entries however, can be badly spelt and your word GABLE and GALLE are a pretty close match to me.
Personally, If there's no more options and you've checked the books on place names, I'd say that they were one and the same.
What do the rest of us think?