I find it very interesting that the tach roller cap on the 55-8 lacks the finger indentation...the cap is (obviously) still exposed, but it sits flush with the head-cover making its exposure somewhat superfluous you know? Interesting. Maybe that was an early iteration and somebody said "you know, it would be more effective to put an indentation in the roller cap for scrub-control.". I dunno...i like to wonder about useless stuff like that.
Anyway, no complaints here about the old thread revival. Interesting stuff AFAIC.