Mr. Knox, I understand why a repair shop would avoid the manual choke fix. Operator error in use could be the problem that gets blamed on the shop. I put one on a friends decent looking 1958 Pontiac wagon and he drove it that way for several years.
Did the old Pontiac have the choke stat mounted in a well in the manifold? Those were somewhat less of a problem. The greatest problem is attaching the cable in proper alignment and operating the choke. Just like allowing the automatic choke to set by depressing the throttle it is necessary to step on the accelerator before pulling on the choke. ‘Seasoned’ drivers may quickly recognize and deal with the situation… Operator error is a major problem.