Today I came across an enamel spray that is very close to the bright green that Lionel used for many of the postwar accessories (e.g. 153 Block Signal base). It is made by Rustoleum, an engine enamel No. 248951, “Grabber Green”.
This probably would not satisfy anyone looking for a perfect match for that exquisite restoration, but it’s closer to that Lionel accessory green than I ever expected to find in an inexpensive, stock spray.