Years ago I CAREFULLY used a rat tail file to rough up the inside dimension of the eyebolt to afford more grip on the L - rod ... and placed two or three washers ( I forget which ) on the bolt for more slip for an extra bit of pressure between the eyebolt and the rod ... the watchword is go easy, don't force it ever, feel it and don't torque it beyond tolerance ... best is to replace the nut with a wing nut, so no wrenches especially on those vintage brackets