Complex sentence: After immigrating from Scotland in the 1780s, the Murrays had first established themselves as manufacturers of textile machinery before moving into the spinning of fine yarn and the complex was probably originally designed to house equipment produced by the Murray brothers themselves.
Split into simpler sentences: After immigrating from Scotland in the 1780s, the Murrays had first established themselves as manufacturers of textile machinery before moving into the spinning of fine yarn. The mill was probably originally designed to house equipment produced by the Murray brothers themselves.