By the looks of your sig line this one would fit right in. The frame tag says 10/70 for the build date.
Wow! That's right at the peak season for the K1. That's going to be a GREAT bike. Those were the original 100,000-miler bikes. If it still has the stock drive, it will have a 17T countersprocket and a 48T rear sprocket, 115 mainjets with the carb needles in the middle position. With today's fuels, consider running it on less than Premium, so it won't foul the plugs, or switch the mainjets down to #110. Either way, try running midgrade fuels, listen for any knock before going up to premium.
That engine will have Stellite valve guides, hard as nails. Put a little 2-stroke oil in the gas when you think of it, so they will last. Mine went over 100,000 miles with the last 35k or so of it using oil in the tank. During rebuilds now, I install bronze guides instead, but the Stellite guides deliver absolutely great performance.
Yeah, boy, that is one beautiful 750!