I've now managed to complete the full grid. I struggled to find decent pictures of these, but managed to cobble something together from a variety of sources.
The final 3 are:
#24 RETZLOFF CHEMICAL LOLA/FORD DRIVEN BY AL UNSER
#25 GENE WHITE COMPANY MONGOOSE/OFFY DRIVEN BY LLOYD RUBY
#59 CLEAVER-BROOKS BRABHAM/OFFY DRIVEN BY RONNIE DUMAN
So, in tandem with
pack 1 you should have the full grid.
Enjoy!