Ex widow fitter here
T-CUT or CIF(jiff bk then) deffo but dont rub to hard with it ,
also Cellulose Thinners,but use it on the white frames only not the brown frames some of em can go a funny colour.
After if you wanna go the whole hog the car polish Mer rubbed over will stop them discolouring again makes it easy to clean the next time,just dont tell the customer this otherwise they wont get you back,lol
TFR wont get rid of the rubber streaks that bleed into the plastic
Astonish wasn't around then so i cant comment on that