Very cool Chris ! Alloy banjo connectors on upper line ! Wow !
another possible early distinction (i posted on this a few years back, didn't get a any replies) is valve clearance inspection caps. what i don't know for sure is if all sandcasts used the same caps or if there were different types of caps used within the sandcast production run. what i do know is on the caps i've found on SOME sandcast cam covers is the embossed markings "F" and "1" on the inside of the cover. my experience seems to support caps found on non-sandcast machines don't have these markings. and, actually, if one compares the two caps side by side, the caps with "F" and "1" markings are overall very different from caps without markings. i have found both types of caps on sandcasts. i have found caps with markings only on earlier vin sandcasts. how far into the sandcast CB750 production run these caps were fitted, i do not know.
so i guess the bottom line of what i am saying -
what i don't know is if these caps embossed with "F" and "1" are features of caps found on earlier vin sandcasts or all sandcasts or for that matter on earlier vin diecast units.........