[HO455]

Hot roding like many things has trends and eras. Which when mixed and matched don't always work well together. Nostalgia works when it reminds people of their past.
By adding the swooshes and making them look like they are original you are trying to add 1950's hot rodder paint to a 1967 truck. They look out of place since they were out of style in 67. My suggestion is if you like the 50's hot rod look trade your sweet step side for a pre-1960 truck and go for it.
Taking a small foreign car and stuffing a V-8 in and a straight axle under it was a popular hot rodding trend in the 50-60's. As time went past this trend when away but has become a popular theme to recreate unless you step out of era. It is still the same basic idea but, just looks wrong.
Now this is an extreme example but it explains my opinion.