Engine serial is CB750E-2505813 and frame 1005686 so it seems to be '75 all around, albeit what seems to be a very late '75 engine and early frame - made 2/75.
Also found out why there was a very, very neat cutout on the fuel tank flip - it's to clear the boost gauge. Very nice neat minimal cutout - bars have to be turned to the left to let the lid clear the boost gauge.
Popped off the air filter - still no idea what carb it is - need to remove the filter backing plate. Seems to be imperial size bolts, which considering the turbo kit is American, shouldn't be a surprise I guess. When I twist the throttle, a squirt of fuel is injected into the carb - is this typical for 750's? I've only ever riddin my 500/550's at all so am unfamiliar with 750 bits.
Also found the original tool kit under the seat - complete
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