I have that same bumper guard on my 1949 3100. I don’t know much about the guard other than when I bought the truck from the original owner, they said the dealer installed it in 1949.
So when I restored the truck I had it re-chromed and put back on.
There were dealer installed parts, that people like to have, but were not made by GM. I have no idea if these parts are acceptable in 100% restoration show trucks.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."