So Fed needs to reach the Semis at the French Open to Surpass Vilas for the most wins at RG.
Yes. And Nadal needs to win to achieve the same.
It is a bit strange the RG has a record as "low" as 58. In the US Open, Federer is just 6th with 64 wins. In Wimbledon, Sampras' 63 is only good enough for 4th. The AO having 56 as the old record before Fed improved it was less surprising, considering the lower status it used to have.