The 749R was designed to be raced..... Ducati said so.... it was their main aim. You say the tyres have been scrubbed to the edge, then that you are confident that it's not been raced...... Those Japanese roads have really cleared up the traffic problems to be able to do that on a 749R!
No marks on the bolts mean that the mechanic had the exact fitting sockets or that it's never been serviced.