Disassembled the front seats in the E30 as there were a few niggles, sorted all excluding the stuffed backrest shocks, which will be replaced one day.
The drivers side backrest bolster had broken and missing plastic piping and a split wide open seam for a few inches. I sewed a new run of piping using the original nylon core around some spotlight vinyl, then sewed that into the two parts of leather using the existing holes so as to not make a ‘tear here’ line(leather needles have a blade which cuts as opposed to separates the fibres).
Happy with result.