So was or were??? Examples I've just found: Wood is an important natural resource, one of the few that are renewable. The Lehigh Valley is the third-largest metropolitan area in Pennsylvania, and one of the few that is growing. But these days, Chenega is one of the few that still leads this kind of subsistence life. Your package was one of the few that were missed in the fray of preparing our entries. ..and so on and so forth! Seems like both variants are acceptable.