I used these struts, brackets and studs on our GTC.
https://www.ebay.co.uk/itm/PAIR-GAS-STRU...2749.l2649
https://www.ebay.co.uk/itm/PAIR-GAS-STRU...2749.l2649
https://www.autodoc.co.uk/ridex/8335999
I also added a washer on the balls stud to add a little strength to the bracket and tightened it all from underneath with an M6 nut. Struts are 393mm and 180nm and are sold as single so 2 need to be ordered.
https://www.ebay.co.uk/itm/PAIR-GAS-STRU...2749.l2649
https://www.ebay.co.uk/itm/PAIR-GAS-STRU...2749.l2649
https://www.autodoc.co.uk/ridex/8335999
I also added a washer on the balls stud to add a little strength to the bracket and tightened it all from underneath with an M6 nut. Struts are 393mm and 180nm and are sold as single so 2 need to be ordered.