Moustagua
The good news is that all the helmets i made for F1 2019 are compatible with F1 2020. You just have to use the new EEA V7 to install them. If you have the 70th anniversary edition, i suggest you to replace the 70th anniversary helmet that you will find in the folder 2020_assesgroup\character_package\fom01 i guess ( i'm not at home and don't have the game folder under eyes so i tell you that by memory, but it's something like that. Just search in the erp files of the game with EEA V7 to find the good one) Adn like in F1 2019, the helmet files are in several erp so be carefully to replace the helmet in all of them. But this time there is only 2 or 3 erp files with the helmet inside and no more 6 like in previous game.
Moustagua
If i have time, i will try to do it but for now i have a lot of other things to do...so just be patient...