When you say original, do you mean script original style or battery that is currently installed?
Corner brackets;
https://www.snydersantiqueauto.com/P...earchByKeyword
Go down the chart in this link, it shows sizes for 6 volt 3 cell batteries;
https://www.batteryequivalents.com/b...ize-chart.html
If you are going by the size now installed it may one of the others on the chart and not a group 1.