We often call the technique of restoring a gas pump to look like an old original survivor as being a "rustoration." There are many old threads on this forum with photos and discussions about rustorations. Do an internal search to find them.
Click on the little magnifying glass on the upper right near where you click to login.
Then choose the text link, "Advanced Forum Search"
On that search form you can choose which forum sections, time periods and authors to target your search. See attached screen shot picture.
Choose Showcase and General Discussion forum sections.
Put "rustoration" in the Keyword box
Put "MATT ALVAREZ" in the Display Name box as he is our resident rustoration craftsman
Put in a date range of Newer than 7 years and Older than 1 year to narrow the search for speed and accuracy
Look through the links in the search results. Lots of photos and some discussion of technique. Like this:https://www.oldgas.com/forum/ubbthreads.php?ubb=showflat&Number=529938