19.5's were used clear up into the 70's on the bread trucks. (Grummans, et al) Can still be found in the older wrecking yards. Then again, you're in MI, so probably shipping is the killer, eh? Still, there's LOTS of yards within a days travel.

My 1955 GMC 450 Dump Truck
In the Stovebolt Gallery
Elderly Iron
"Performance" is the pursuit of a toy that won't break.