HI Raid,
I suppose once my book comes out and "hopefully" Canon becomes a collectable item then this lens would be classified as a collectable if indeed it turns out to be the first of the T4 variation. The gap between this T4 lens and the previous T3 lens is only 153 units or lenses. Therefore, some where in between the two TYPES Canon changed the format on the ID ring of the T4 to read "CANON LENS CCCo Japan 85mm f: 1.9". I have described the reason in my book why Canon made these subtle changes to there lens and each time it coincided with an important event, which was happening in Canon at that time. As I receive more information on lenses serial # that are outside my listed numbers then that gap will come down until such a time that we will have a last and first lens of a TYPE. This makes collecting a challenge. I suppose I have been lucky as I have been researching I have been in the fortunate position to recognize an unusual lens and purchase it. Ok enough of my dribble but the research has been interesting as well as satisfying. Peter