OK., well if your going in that direction, then I would suggest " more ORIGINAL than not" as the subject title.
Besides all the consumables that
most/many bikes have replaced,i.e. hoses, light bulbs, oil, filters, shoes/pads,brake fluid, tires, cables etc..., consider that paint/decals/emblems, chrome, jets, exhaust pipes / mufflers, seat covers/trim, petcock, fuel tank, oil tank,etc... are often replaced or rebuilt as well.While replacement parts maybe stock parts, they aren't original to the bike they now reside on.
My 78 has little that isn't original, which is to say that didn't come with the bike, aside from the oil/fuel/filters/battery. I believe it was as sold to the Original owner when I bought it from him. However much has indeed been painted/powder coated and modified to some extent, yet the parts are the original parts to the bike itself so it all depends on the definition of "stock" that you are applying on this forum.
Aside from what I consider "consumables" that have been replaced, so too the exhaust, pods, tail light assy.,license plate, side covers, grips, rear shocks and oil pressure gauge are neither stock nor original, hardly more than 50% of all the parts involved in a stock or original bike.
If you want to include paint or plating, then remember everyone that has repainted/re-plated their parts/bikes, unless they somehow managed to get the original Honda paint or plating, not just the original stock colors/finishes, has an altered bike or parts thereof. Then there is the lack of a definitive way to prove that the "original" fender you bought to replace the one your bike didn't have or was damaged beyond repair, has the original chrome from Honda or has been re chromed by someone else, or the tank that you bought has the original paint not just an original colored paint etc...
Then by the "loose" definition of stock, A 69 750 that came from the factory with the actual sandcast cases had them replaced after failure is no longer 100% original but still stock, or if I resurrected a basket case and replaced a 78 drive train in a otherwise complete and stock 78 frame is that still within the definition?, and would it still be if I put an all stock 750 f1 engine in a k chassis?, etc...,
So, since I
KNOW that well over 50% of the parts on the bike in the picture are original, what are the criteria for the definition of the subject: the sum of the original or stock parts, surface area, weight, mass, volume, geometry, adjustments, performance, speed, quickness, torque, horsepower, cornering angle, ground clearance, tire size/sidewall ratio, tread pattern, gear/sprocket ratios, or any other quantifiable aspect of the 1978 CB 750 K as delivered from the factory.
And then there is the fact that most of us were not able to buy these wonderful machines new and then watch and witness their packaging, delivery and subsequent assembly at the dealer before we purchased it, therefor there remains a possibility, and a probability as well, that your 100% stock bike isn't...
And finally, if the Moderator or anyone else really wants to object to my efforts, then by all means remove the original post, I only wanted to participate in, and become part of the community of enthusiasts here with which I share a affinity for said machines, if I am in error or not welcome then please let me know forthwith and i shall not bother you or anyone anymore.
And to you evanphi, pedantry abounds within all forums I have read or been a participant in, therefor your enjoyment must be great indeed!!