here are a couple, of several, I made years and years ago to replace the stock poles on the LGB dis-connects. They were made very much like Eric described above. I used 14 gauge copper wire but flattened it after bending the loop. Not sure why, just seemed like the thing to do. I used a piece of 22 gauge black iron bent to cover the top and down the face. The holes for the loop were drilled and the wire set in Epoxy. The "bolts" in the top are short finish nails with the head filed square to look like old, what else, square head bolts.
These shown are 4 inches long, I made some in 6 and 8 inch lengths as well. Oh, the wood is old growth Redwood 1/2 X 1/4, sorry the picture is a little fuzzy.