Reckon your best bet Tony is to get a used one of these from Luke :
https://www.volvopartswebstore.com/p...9/8250262.html
Link provided as description only, the 7xx part supercedes the 940 part and appears to be NLA at Volvo, not that you'd want it to be available at nearly 100 bucks!
Alternatively, find an M10 x 35 bolt and weld it in place on the horsehoe bracket.