Couldn't help myself but I found some further images of Ronnie Petersen and Jacky Ickx helmets so have updated and included as alternatives to those already present in the skin packs & mod listed below.
Helmets are:
Lotus 72D - Ronnie Petersen
Lotus 72D - Jacky Ickx
F1C75 Lotus 72E - Ronnie Petersen (same as 72D)
F1C75 Lotus 72E - Jacky Ickx (same as 72D)
RSS Formula 79 JPS #6 - Ronnie Petersen
RSS Formula 79 Ligier 25 - Jacky Ickx
Skin Packs/Mods:
Lotus 72D Formula One 1975 skin pack
By clemenskaa
Available here: https://www.racedepartment.com/downloads/lotus-72d-formula-one-1975-skin-pack-22-cars.21137/
1979 Complete Season Skinpack - RSS Formula 79 - 4K
By thejqka
Available here: https://www.racedepartment.com/downloads/1979-complete-season-skinpack-rss-formula-79-4k.48224/
Formula One 1975
By Bazza
Available here: https://thracing.de/formula-one-1975/
Helmets are:
Lotus 72D - Ronnie Petersen
Lotus 72D - Jacky Ickx
F1C75 Lotus 72E - Ronnie Petersen (same as 72D)
F1C75 Lotus 72E - Jacky Ickx (same as 72D)
RSS Formula 79 JPS #6 - Ronnie Petersen
RSS Formula 79 Ligier 25 - Jacky Ickx
Skin Packs/Mods:
Lotus 72D Formula One 1975 skin pack
By clemenskaa
Available here: https://www.racedepartment.com/downloads/lotus-72d-formula-one-1975-skin-pack-22-cars.21137/
1979 Complete Season Skinpack - RSS Formula 79 - 4K
By thejqka
Available here: https://www.racedepartment.com/downloads/1979-complete-season-skinpack-rss-formula-79-4k.48224/
Formula One 1975
By Bazza
Available here: https://thracing.de/formula-one-1975/