As Excelsior Springs Chamber of Commerce Director Brian Rice will attest, perseverance pays off – particularly when it comes to securing a grand marshal for the Waterfest Parade. Sam Webb, now in his second season in pro football with the NFL franchise the Las Vegas Raiders, will be the grand marshal for this year’s parade, scheduled to begin at 9:30 a.m. Saturday at Marietta Street. It took two attempts to land the 2016 Excelsior Springs High School graduate, Rice acknowledged. “When we were talking about grand marshals for 2023, Sam was the first one that … (came) to our minds, and a couple of people connected to him – reached out to him – and invited him to be our grand marshal,” he said Wednesday morning at the chamber offices. “Unfortunately, at the time, he had some NFL scheduling things that he was obligated to and he had to decline.” The chamber then spent a few months pursuing an alternate, Rice said. Briefly under consideration was hip hop artist Mac Lethal, a Kansas City…