x <- list(data.frame(a=c(1,3,4)),
          data.frame(v=c("B","C","A"), w=c(12,14,17), h=c(1,2,3)),
          data.frame(m=c(2.2,4.1,5.0)),
          data.frame(h=c(4,1,2), u=c(9,7,2)))
conv <- c(FALSE, TRUE, FALSE, FALSE)
x

x <- list(x[[1]], x[[2]][1], x[[2]][2], x[[2]][3], x[[3]], x[[4]])
x