A few years ago we went through this for a 69 restoration and I gave up on getting the original look with today's processes. We have a number of the parts galvanized by a couple of platters that do it all the time and we ended up with a finish unlike any of the originals. It was thicker, caked on product rather than the thin plating with clear large geometric shapes we were looking for. So instead I had them stripped then zinc plated which I used as a base to do faux plating with multiple layers of different colored shapes which IMHO turned out well and was acceptable to judging and people looking at the car, ie passed the eye test
Multiple people have used the technique to redo or simply repair sections on a fairly nice original plated part with success
If your the same
astat1 as the one on CMF check the Library there for an article on how we did this process.
Pictures are not a true representation of what the finish looks like in person or from different angles like the real galvanizing
On a couple of the larger pieces we reproduced the ink stamp that was applied to the sheets of galvanized metal used to stamp some of the larger pieces from, for an extra detail found on some original panels
Creating one of the layers
Hope this helps