Welcome to the forum. Great pics which look 100% better with the white gone. Might be able to get some $$$ for those vintage bags and fairing on eBay to help supplement your bike project. Here is some info on the K1 & K2 model for you. Looks like you have a K1 model which was built in 1971 and not sold and titled until 1972. I don't know that it would be a benefit to try and change the title as long as you list it as a K1. Sort of depends on how strict your state is and how hard it would be to change. Stop in at your DMV and run it buy them. I have one of those strange ones too. I have a K1 built in 9/70 and titled as a 1970 because it sold that year.
The CB750K1 Four was sold from 1970-71 and was available in one of four colors: Candy Ruby Red, Candy Gold, Valley Green Metallic, or Candy Garnet Brown. The gas tank stripe was gold. The tank, side covers, and upper forks were of the basic color (red, gold, green, or brown). The side covers were smaller and there were no slots on the leading edge. There was a two-throttle cable system (pull open and pull closed). The headlight shell was also the basic color. The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. Honda CB750K1 Wiring diagram
Serial Number
Frame: CB750-1044650
Engine: CB750E-1044806
The CB750K2 Four was sold in 1972 and was available in one of three colors: Brier Brown Metallic, Flake sunrise Orange, or Candy Gold. The gas tank stripe was gold but as with previous models, the Gold tanks had a black stripe. The side covers were smaller than the K0 model and there were no slots on the leading edge. The upper forks were chrome. The headlight shell was black. The taillight and side reflectors were larger. There was a two-throttle cable system (pull open and pull closed). The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive.
Serial Number
Frame: CB750-2000001
Engine: CB750E-2000001