Welcome to Chevy Chatter!!! You picked the right place to get answers about your '42 Chevy.
And, if you join the VCCA, you will gain access to additional "members only" Forums here on Chat and an absolutely great magazine called the G&D (Generator and Distributor). So think about that!!!
Now for your questions.......
The engine color should be a dark gray. It is readily available from the Filling Station....
https://www.fillingstation.com/catalog/flippingbook/index.html#359/z....top of the page under "Engine Enamel".
As far as the fog lights you mention, I can't really help.....but look through the Filling Station catalog and you just might find some repros that are close.
Any future questions you have might get more attention if you post them in the 1937-1942 Forum a little further down the page.
Have fun with your restoration and let's see some pictures!!!!