I've got one of the nylon wingnut skewers, but I think the shaft is steel. I also have a 36-hole Hi-Lo hub that, thankfully, has 18 holes in each flange. I recall just a few people running Hi-E stuff in the 1970s. The hub bearings didn't seem to be too durable, though I ran a set of hubs on a Masi for a few years and only picked up a small amount of play. You have to remove the spokes and pull off the flanges to change the bearings, which you don't need to do with Phil Wood hubs. The rims were considered suitable only for time trial use among the riders in my area. Since vertical dropouts were rare in those days, the skewers were only used in the front. I always liked the minimalist look of the metal cone skewers, though you were screwed if the peg came out on the road and you flatted, unless you had something that would fit in the hole and then you likely wrecked the skewer. I had a strong distaste for the waterbottle cage the very first time I saw it. I hated the hose clamp mounts and the things seemed creaky.

BTW, the rims don't have a seam in the common sense. The sheet is simply overlapped across the spoke holes and riveted together.