This is the neighborhood my grandparents and other family lived in for many years and where I spent many, many happy times as a child. I am sure there is no ill intention and it something that gets picked up in vernacular, but there was some bad history and difficult times that lead to the "Jamaica Spain" moniker, can you just call the old neighborhood, J.P. as one of those with fond memories of the old neighborhood. Jamaica Plain or JP work well.