Re: 55 hp chrysler
There are probably used CDI boxes still available for that engine. I don't think you would want to invest in a new one. Try over at The Chrysler Crew. Place a want ad in the classified column. If you want to spring for the big bucks for a new one, then try franzmarine.com
You can convert to either standard magneto ignition or battery powered points and coils, but really, if you can get a used CD box for about 100, then why go to the trouble and cost of converting.
And it is possible--I don't know--that Evinrude had the same CD box. I do know that at one point OMC and Chrysler used the same trim/tilt pump and motor. They all outsourced things like that so Motorola may have also supplied OMC with electronics and like you say only the wire color might have been different.