A little more info by Googling.

Looking at the Evans Early American Imprint Collection I can find no reference to items printed in Salem before 1750, but many early pieces were printed in Boston and sold in Salem as we see with our example.

However by 1800 Thomas C Cushing was printing at the Bible and Heart in Salem.

There was also an imprint 'Printed and Sold at the Bible & Heart in Cornhill, Boston' in 1776. So there was a B&H in Boston and in Salem. My guess would be that our broadside was printed at Boston in the 1720s and sold at Salem, and this outlet eventually acquired its own printing press by 1800.