try working from the underside with that iron be careful with thin plastic areas and adjust the heat as necessary. i used a folded wet towel on the good side as to keep that side from deforming as best as possible play with it in a spot you will never see first to get a hand with it. and if you can get some of the same plastic from areas that wont affect it you can use it to fill. if you need a backing you can use some brass screen to embed into the plastic this type of stuff https://www.ebay.com/itm/40151735385...iABEgLF8_D_BwE you want something that will allow the melted plastic to come through the pores so too fine a mesh will not help. brass does not rot so the fix should last if done properly. you also do not want to char the plastic with heat as it will lose its bonding abilities. with the right temp the plastic should just move easily and not change color.