If I understand correctly you propose to build a Bridget. I can't provide a definitve answer to your question but I do know the Bridget boiler fairly well and it would be reasonable to assume that Ken Swan adapted at least the details if not the entire Bridget boiler to Jessie. From measuring two small elevation drawings the OA length and other major dimensions appear to be the same but that could very well be misleading. I would be glad to quote and compare OA dimesions with you if you wish.