Frank, you don't have to limit yourself to clip art either. I have often used the IAM Symbol (International Association of Machinists) on some of my toolboxes, and added interest with micrometer shapes, the Local Number of my Union and added letters. I've also included the insignia for the railroads I worked for, and even included such things as a Maltese Cross for a model Fire Truck I did for the local fire department.
With a little creativity, some internet searches and a bunch of scrollsawing, you can make just about any symbol.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"