gearhead56,
biggreen48 is right - Forrester Green was not available in 1954. Juniper Green was the standard color and is the only dark green in 1954 (Ocean green was available but Seacrest Green was not). Bob Adler's article in November 1998 Pickups 'n Panels in Print states that the PPG color code has not changed and is current (lil' johny mentions Bob in his earlier response to your query and gives the correct PPG code).
It is impossible to know how true modern paints are because paint chips fade and the dyes/tints used in paint mixes change. In addition, the old codes/mixtures are often no longer used.
I have had luck with finding matches from PPG (Acrylic Enamel and Acrylic Urethane) but have misplaced the phone number (they have a special office/service/library for finding matches/offsets to old codes). I found the phone number by checking their extensive website - I found a number for their color library.
The DUCO (Dupont code) for Juniper Green is/was 618-G and the stock order and code numbers were 1618-H and 246-72001-H; the DULUX is/was 93-72001; the Comb No. (I do not know what this meant) was 528).
Ditzler's code was DQE-41374 (enamel) and DAL-41374 (lacquer) - Ditzler might have become or been bought by PPG.
I also have ACME and PER-MAX color codes if you want them.
By the way, quality paints ain't cheap. Good luck keeping it looking original.
Tim