The fuel cap has a doubler around it. This is due to the fact that the boot cowl was not splitted. When fitting it, a couple of rivets broke around the fuel cap area and this is purely a repair to that. They say that "in the good old days" you would get the boot cowls without rivets on the bottom side, so that it could be fitted more gently.
The last pic is the gascolator. I was adviced to use "Steve's Aircraft" Gascolator by friends at the Clyde Smith restoration seminar in Denver. It's a solid gascolator, and we needed to use a doubler in order to get all 4 screws fastened (the pre-cut hole was not right for the bracket). Admit it: it does look expensive! (...and it was...)
We should be all ready for engine installation next week unless my employer sends me off to Nebraska again...