I am hoping someone can offer some ideas on this problem. The small diameter of the "head" is only part of the problem. The head goes over two metal rings. The upper one has a rounded edge on the top, simila to a rolled or spun meta tone ring. The underside of this ring has a channel which mates to the lower metal ring. The edge of the lower metal ring has a shallow groove . The purpose of the groove is to provide a place for a piece of wire to go in. The wire serves the same function as the much larger diameter ring used to mount a calfskin head on a banjo. I have been unable to get the piece of wire to go into the groove all the way around and have the outer edge of the calfskin coming back up.The diameter of the wire is determined by simply twisting the two ends. I end up with being unable to get the wire on over the skin or it is too large a diameter and goes beyond the lower ring. I tried a belt clamp and even tried using neodymium magnets. I feel like I could do the job if I had six or eight hands!
At this point I am beyond the point of making a profit when I sell the banjo uke. But, the challenge keeps me going.