i have a Widow, getting parts for any of the last 3 Trinity 1/12ths cars is tough. luckily the Widow has the ability to cross utilize more parts from other 12th cars.
You can use a AE 12L4 antenna mount...direct fit, any 4-40nuts thick or thin as needed, AE 12L4 T-bar carbon brace...of course it won't connect to the antenna mount like the Trinity one does, as for the standoff you may have to shorten a AE 12L4 center post to fit you car.