The guest bath rebuild which looks like 80’s is far worse than I thought it was, the mold below the sink was very bad, always use precautions when working with mold and paint that may contain lead.
I tested for lead at the guest house bathroom and the results were negative. I’m sure lead will be found somewhere, however the guest house bathroom was added to the former kitchen (Now guest house) at a much later date. The wall insulation behind the shower walls was date coded 1987