Hi Wayne,
Your plan sounds like a great one !
Before i start any restoration project, i always obtain the parts and service manuals to study, then i compare what i am reading to the parts making up the actual bike, before, during and after the dis-assembly of the bike.
Did you get the bike yet ?
Yes, Parts Manuals are available, if you want original, your best bet is keep a regular eye open on ebay.
If i recall correctly, the first printing was April 1969, followed by a July printing. These early printings are somewhat rare and expensive. I am not sure what the print date is on the latest CB750 manual. And, quite a few part numbers are correct only for the early vins and not carried over to later vins, in other words, if you look for parts using the pn's from an early manual, these pn's may come back as no longer available, due to being superceded. And, with these early manuals, parts that were used on later vins, are, for obvious reasons not found in the earlier manuals.
After the CB750 manual, comes the K1 manual, the first print date, if i remember correctly, is February 1971. This manual has many of the updated and superceded notations for the CB750, including early vins such as yours. In my opinion, the first printing K1 manual is the best of the lot, it shows in much detail, the changes the CB750 underwent, both from design changes as well as supercession.
Otherwise, if you don't have to have an original parts manual and a copy is ok, someone of us would probably be happy to make you a copy. i have both manuals mentioned above.
As far as Workshop Manual, i like the factory manual the best, they really do a a nice job, as good as any aftermarket manual and it has all the factory pictures in it. I am not sure what the print date ofthe first workshop manula was, i have a 7/69 in rough condition and an 8/69. There was also a thin provisional workshop manual with a print date of June 1969, much different from the typical green covered manual. Either a Clymer or a Chilton's is good as well, i don't care for the Haynes. You can buy an original green cover CB750 manual for a reasonable price, if you don't have to have an early print date, as far as i know, they are all the same. The same CB750 manual was used for the K1 also, there was a K1 (thin) supplement with a brown cover that addressed the service considerations unique to the K1.
Please note, i refer to both these manuals as CB750 manuals, becasue this is what the factory called them. They were not called "K0"manuals, because it was quite some time later before Honda started using the model designation "K0" in any of their literature. If i recall correctly, Honda started using the term "K0" sometime in the early 80's. If anyone knows when the term "K0" was first seen in Honda literature, please post the evidence !
I have not ever seen a K2 onward service manual, but i will assume the manual is referred to by Honda as servicing K2 models.
The factory parts manuals, i have CB750, K1, K2, K3-6 manuals, Honda uses the "K" designation in their manuals all the way from K1-K6, with exception of course, to the 69-70 CB750's from vin 1-44649. "K0" was never a term that was seen in any period factory parts manual, AT LEAST THAT I AM AWARE OF ! The designation of "CB750" was used by Honda in distinguishing machines from vin #1 through 44649. Honda made no distinction bewteen sand and pressure cast bikes in any of their literature, including parts or service manuals, again, AT LEAST THAT I KNOW OF !
But, there is much more to be learned about the CB750, more than we will ever know in our lifetime.
WHEW.......... ! I went off on a tangent there, but i LOVE factory literature as much as i love the actual motorcycle. I collect every piece i can find.