realmccoy, Before I bought the truck I have now, I owned a 1951 Chevrolet four door sedan. When I first bought it, the steering as bad as what you describe in your 52 Coupe. Most of the slop was in the idler arm. As you know, the rebuild for that is similar to a king pin. I brought the assembly to a machine shop so they could fit the bushing and the pin.
I ordered the Kanter front end kit and used all the parts that came with it. I did the upper and lower inners and outers on both sides, replaced the king pins and re-bushed the stabilizer bar. I also replaced the tie rod ends. This was all about 6 or 7 years ago so I cannot remember exactly how long it took to do the job. It seems like it took two or three full days to finish it.
I think the fact that your son is going to use this car as his daily driver would answer the question of whether or not you should do the complete job. Steering and stopping are the most important safety features of any vehicle. The brakes sound like they are in good shape, the steering and front suspension should be in good shape as well..
