Were they .40/90 bottle necked?
Would have been on the .45 case, so close to .500 or so.
Just remembered - there is another way of putting the brass tubing over an undersized base with close to the correct rim diameter.
The brass tubing I am talking about, is the material available at (here) model airplane hobby stores. It comes in sizes from very tiny, to 1", in .015" steps. Each successive size, slides into the size .015 smaller. So - all have a .015 wall and they are always within .0075" of being the correct size.
Silver bearing soft solder works.
.015 x 2 + .030" total over case base diameter.
If .487 is needed, then perhaps a .405 Winchester case could be used with a sleeve. A .405 Winchester case at .460", + .030" is perfectly capable of beind sized or trimmed to .487".