In my opinion, we have now found the correct family, and parents for your George Williamson, and confirmed this through shared addresses on various documents.
Georges parents death certificates are both available and should give you the names of Georges grandparents. Are you able to let us know who they are?
We have established that your George was probably never married to Jane Peel, and we havent found a death certificate for George.
It is also difficult to see a death in Scotland for his brother William (with the extensive prison records). His other siblings seem to be traceable.
I wonder if George and William ended up moving away (either together or separately) to England, Ireland or further abroad?
That would be something to consider for future research. In my glancing at records, I did notice that some members of the extended Williamson family had gone to Canada & USA.