It's all academic since Stable Version 1.86 is in use but here goes anyway.
Removing just the f's does work. As to the eyeVector variable. The original line 291 was as follows:
vec3 halfVector = normalize(lightVector + eyeVector);
This was tweaked to remove only the eyeVector variable resulting in this:
vec3 halfVector = normalize(lightVector);
Both of these tweaks will allow the new oolite-default-shader.fragment to load in v1.86 with an older version of OpenGL. As for the usual "Shift Key - Reload It All" step that happens every time Oolite starts as my .GNUstepDefaults is tweaked to force this as default behavior. Takes a bit longer to load the game but it saves a minor bit of hassle when tweaking files with a forgetful brain.
A noticeable difference in the lighting effects was evident once both of these tweaks were made to the updated oolite-default-shader.fragment with stable v1.86 even if it was not the full effect. Of particular note is the way light moves across the hull of a ship while it is in motion which is easily identified with the spinning ship in the Ship Respray OXZ. Liking the way things look even if it is not the full effect.
To Trunk Or Not To Trunk, That Is The Question.