I don't think it has been mentioned yet, but the date range of the OP watch is likely 1964-ish to 1966-ish and so unlikely to contain radium.
It's a combination of the light-weight balance, yet fixed stud carrier along with the 951xxx serial number that pegs it.
Sometimes the lume on these watches fades to tan or brown and sometimes green or blue, often a light fade.
The EP40-68 was introduced in 1968. Prior to the EP-40-68 designation, the movement went through a small number of changes beginning a couple of years earlier - this according to the folks at Gallet.
I agree that mint examples are in the $5000 and up price category and sometimes can be found for less, but because of the association with Jim Clark, some people pay a bit more for this watch in poor condition than they probably ought to do.
He's my 1968 to 1970ish watch, EP40-68, S/N 955xxx
When I bought it, the hands were a bit rusty and the lume on the central hours and minutes hands was in sad shape. I had the watch serviced and the hands relumed at RGM in Mt. Joy, Pa.
Here is a "before" shot:
Some folks are not bothered by what they will refer to as a "fine" or "attractive" patina, but to me it just looks like damage.
I also agree with those who suggest that, if you like the watch and intend to keep it than get it serviced, otherwise don't spend any money on it.
Edit: My MC 12H "JC" has a taller and smaller non-original diameter replacement crown. The OP watch has the correct original crown.
Second Edit: Added the words "unlikely to contain radium" for my own protection.
馃槈 The movement and the serial number range suggests a mid 1960s date of manufacture and brown tritium lume is not unusual for this watch.
